Note: Most parameters here are given for argon ion tubes since these are most common. However, while physically interchangeable krypton and mixed gas ion tubes are very similar electrically, they will have slightly lower starting and operating voltages. This isn't a problem for starting, but the difference in operating voltage can be significant enough to cause some power supply compatibility problems such as excessive power dissipation in the regulator circuits. This should be kept in mind if substituting tube types. See the section: Comparison of Argon and Krypton Ion Tube Characteristics for a specific example.
The source for the operating voltage is either a direct line-connected rectifier/filter 'front-end' or this followed by a high frequency inverter.
A series linear or switchmode (buck) regulator may be used with the line connected supply. Inverters will use PWM control of their drive.
A simple low voltage power transformer with a centertapped secondary usually supplies the filament current. Fine adjustment of filament current can be done using a tapped primary or Variac. The use of AC is actually beneficial and helps to spread the heat from the discharge over the extent of the cathode (filament) by dithering the arc position.
A design discharging a capacitor into a high current high voltage pulse transformer is normally used.
Large frame Ar/Kr ion tubes can be over a meter in length and nearly everything about them is, well, much larger. :-) There are even 8 FOOT (2.5 m) long monster medical lasers that output 35 W or more and require over 600 V at 35 A to power the tube. Figure on a direct feed from a local electric utility substation for this kind of power! Ion lasers like these may also have axial permanent or electro-magnets surrounding the tube to concentrate the discharge and other 'stuff' that we will kind of ignore. ;-) They also require several gallons per minute from a tap or chilled water source to prevent a melt-down.
For these reasons, while the offer of a cheap or free large frame ion laser may sound tempting, consider the power and cooling requirements before dragging it home. It will likely end up as a coffee table support or high-tech sculpture if you don't have industrial strength three-phase power at your disposal! Cooling water may also be a problem. Nonetheless, most of the basic information on small air-cooled ion lasers DOES apply to their bigger brothers as well if the numbers are adjusted appropriately. And, the power supplies are quite similar. In fact, the same power supply can often be used for a wide variety of ion lasers by selecting the AC input and changing some jumpers.
Throughout this chapter, references will be made to several commercial Ar/Kr ion lasers systems. Two of the most common are:
A few oddball versions of the 60X (60XB and 60XC) are still manufactured but the 532 is an obsolete model. American and Omnichrome both make/made a few zillion variations on the same theme. All of them look similar and have common features. American still makes replacement tubes for the 60X but they do much higher power with newer generation technology. Call ALC and request a generic brochure if you are curious (or more than curious).
Photos of Various Laser Systems, Power Supplies, and Components has detailed views of various argon/krypton ion lasers including examples of the 60 series from American Laser Corporation. However, note that the ALC power supply shown in the photos will drive the same laser heads, it is NOT the same implementation as the Omni-150R described in detail in the section: Omnichrome 150R Power Supply and 532 Laser Head (Omni-150R/532). They differ physically as well: The ALC (there are a variety of versions) is in an elongated goldish-aluminum ("Alodined") box (as in the photos) while the Omni is shorter and painted black.
Unfortunately, most of this did not work with Netscape V3.04. Perhaps, it will work with your browser and/or the problems have since been corrected.
See the section: Laser Safety with respect to the optical hazards associated with these higher power lasers. While generally not in the metal cutting class, careless use of Ar/Kr ion lasers can certainly result in instant and permanent damage to vision. There are all going to be at least Class IIIb and some are CLASS IV.
However, when compared even to large HeNe lasers, there are many additional very real dangers associated with Ar/Kr ion laser power supplies:
In addition:
Some basics:
For small air-cooled tubes, the power supply runs off of single phase 110 VAC and deliver around 150 VDC to the regulator. High power lasers will run off of 220 VAC, 240/208 VAC three-phase, or something even nastier to produce up to 600 VDC at 45 A OR MORE!
Note: Throughout this document, we use 110 VAC as the nominal line voltage in the U.S. However, the actual measured voltage may range from about 105 to 125 VAC and still be considered to be within acceptable limits by the utility company. For this single-phase system, using both Hot legs of the line will then result in a nominal 220 VAC which may actually range from about 210 to 250 VAC.
A buck-boost autotransformer (NOT isolated!) may be included to more closely match the line input to the requirements of the ion tube thus reducing the stress on the regulator (see below).
This is the simplest (!!) sort of approach to take for these tubes. For testing, a 5 to 10 ohm ballast (possibly variable) resistor and a Variac can be used (without a regulator) as long as one eyeball is kept on the current monitor. Of course, the ballast resistor needs to be able to dissipate several HUNDRED watts - the element of a space heater may work well for this. See the section: Constructing Low Ohm High Power Resistors.
This can use a pass-bank of power transistors operating in linear mode (which makes a nice space heater for colder climates) or as a chopper operating as a switchmode buck converter. (Note, however, that the latter type is usually still line-connected - there is NO isolation transformer.) The Lexel-88 and ALC-60X/Omni-532 (150R) power supplies are typical of each of these approaches, respectively.
Such high power inverters can be tricky to design. One approach I have considered is to use the salvaged inverter from the solid state power supply from some model microwave ovens. (However, these modules are sort of rare since the simple half wave doubler operating from a HV line power transformer/HV cap/HV diode is such a low cost reliable design and not very models used them.) The power supply for a full size oven is normally designed for at least 1,000 W (which is ideal) but at too high a voltage (3 to 5 KV pulsating DC rather than the 100 to 110 VDC we need). However, by rewinding the secondary of the ferrite transformer (only a few dozen turns of heavy Litz wire would be required) and adding some primary side filter capacitors, it could be adapted to an Ar/Kr ion laser application. I have not tried this as yet but have one such module sitting around impatiently waiting for its call to duty. :-)
See the section: High Frequency Inverter Type Microwave Oven HV Power Supplies for more info on these modules.
Therefore, for all of these reasons, the voltage multipliers, flybacks, and HV pulse transformers typically used with HeNe lasers cannot be pressed into service for starting Ar/Kr ion tubes. In addition, the full 10 AMPS or whatever of operating current would need to pass through them once the tube starts (with the HeNe, it is just a few mA).
The usual way to generate the starting voltage is with a high current pulse transformer. One design uses a toroid with 30 turns on the secondary - in series with the anode - and a 1.5 turn primary. Discharging a 1 uF, 400 V capacitor into the primary results in an 8 KV output pulse. There may be resonating and snubber components as well. Care must be taken in design to minimize undershoot on the secondary - which can just as easily blow out the discharge as well as start it!
This type of pulse/resonant igniter is almost always required for older and larger ion tubes. However, for some 'small' short bore designs, other options may exist. See the section: Alternative Starting Circuits for Small Ar/Kr Ion Tubes.
Salvaged microwave oven transformers with the HV windings removed work well in this application. In this case, simply 'adjusting' the number of turns on the modified secondary may be adequate for setting filament current.
If you really have no choice, or just like a challenge, by far the most straightforward approach is to use a line connected rectifier/filter with a linear regulator. While not quite as efficient as a switchmode or inverter type, the hassles are fewer and parts are more readily available. For initial testing, a low value high wattage ballast resistor can substitute for the regulator. Just don't be tempted to leave it this way permanently. And, in any case, don't neglect the essential current monitor!
Note that if all you want to do is test a newly acquired Ar/Kr ion tube, there may be a considerably simpler alternative to a continuous high current power supply. See the section: Pulsed Operation of an Ar/Kr Ion Tube.
The igniter (starter) circuit may operate off of this DC+ supply or an additional low current 'boost' source to use a higher voltage (which reduces the turns-ratio of its high current pulse transformer - a hard to wind (or high cost) part.
The current regulator uses bipolar or MOSFET transistors in a linear or switchmode (buck converter) configuration. Feedback based on current, light (beam) sensing, or an external modulation signal, is used to maintain the proper discharge current through the tube. For initial testing, this can be done manually using a high power adjustable ballast resistor and possibly a a large Variac on the AC line input to the power supply.
+----------+ DC+ +-----------------+
H o------| |-------------------------| Igniter Circuit |-----+
| Main | +-----------------+ |
AC | Bridge | |
Line | and | +------------+ Light Feedback (option) |
| Filter | DC- | Linear or |<-------------------------+ |
N o------| |-----| Switchmode | F1 +-----------+ | |
+----------+ | Regulator | +------|-+ | )-+ |
| | +------------+ | | ) |-|-------+
| +------+ | | +----|-+ | Tube+
| ) +---|---------+ | F2 +-----------+
| Filament )||( | | Ar/Kr ion tube
| Supply )|| +---+ Tube- |
| )||( |
| ) +---------------+
+----------+
This type of supply with a linear regulator would be the easiest to construct.
While efficiency is lower (abysmal instead of just terrible - probably about
40% more heat generated than for a well designed switcher), the difficulties
of implementing a robust and fool-proof Pulse Width Modulator (PWM) controller
are eliminated. Just provide a large enough heat sink and jet turbine driven
cooling fans!
Since everything except possibly some logic or low level analog circuits are directly line connected, great care (even more than just considering the 1,500 W or so of raw power we are dealing with!) must be taken in the basic construction, testing, and adherence to ALL safety precautions, implementation of ALL safety, electrical, and thermal interlocks and protective devices. In many cases, even that control circuitry is line-connected as this simplifies the implementation since no isolated interfaces are required.
The igniter (starter) circuit may operate off of this DC+ supply, a separate winding on the inverter transformer, or an additional low current 'boost' source to use a higher voltage (which reduces the turns-ratio of its high current pulse transformer - a hard to wind (or high cost) part.
Feedback based on current, light sensing, or an external modulation signal, throttles the DC to DC inverter by Pulse Width Modulation (PWM) - controlling the duty cycle of the drive to its chopper transistor(s) in a manner similar to that for controlling a series pass switchmode regulator. However, there are added design considerations in dealing with the characteristics of the high frequency ferrite inverter transformer.
+----------+ DC+ +------------+ +-----------------+
H o------| |-----| DC to DC |------| Igniter Circuit |-----+
| Main | | Inverter | +-----------------+ |
AC | Bridge | | --+ +-- | |
Line | and | | )||( | Light Feedback (option) |
| Filter | DC- | )||( |<-------------------------+ |
N o------| |-----| --+ +-- | F1 +-----------+ | |
+----------+ +------------+ +------|-+ | )-+ |
| | | | | ) |-|-------+
| +------+ | | +----|-+ | Tube+
| ) +---|---------+ | F2 +-----------+
| Filament )||( | | Ar/Kr ion tube
| Supply )|| +---+ Tube- |
| )||( |
| ) +---------------+
+----------+
While still very dangerous to troubleshoot, at least the main tube circuits
are isolated from the AC line by the inverter transformer. Aside from the
slightly reduced risk of frying yourself, I would probably not recommend the
inverter approach unless you already have its foundation such as the HV power
module from a solid state microwave oven!
For more information, see the chapter: Ar/Kr Ion Laser Power Supply Design.
A .1 ohm 50 W power resistor will develop .1 V/A across it resulting in 1 V at the maximum likely tube current of 10 A. The shunt must be stable with respect to temperature (which is one reason for using a 50 W resistor when the maximum sustained dissipation is only 10 W). The system should then be calibrated with the actual voltmeter or mA meter to be used.
While a VOM or DMM can be used, it is really best to have a dedicated meter for continuous discharge current monitoring. There are two reasons:
One way to implement a permanent current monitor is to use a basic panel meter. This can be a moving coil (D'Arsonval) or digital type. Add a variable series resistor for calibration using the current shunt. For example, a meter rated at 1 mA full scale will require a total resistance of 1K ohms (for the meter itself and current limiting resistors) connected across the .1 ohm shunt to read 10 A full scale.
Rs .1 50 W
Tube- o======+==================/\/\=================+======o DC-
| |
| +--+ M1 |
| R1 | v R2 + +--------+ - |
+---/\/\---+-/\/\--------| 0-1 mA |-----+
940 100 +--------+
Calibrate 10 A Full Scale
Splitting the current limiting resistor into the fixed R1 and Calibrate pot
(R2) allows easy fine adjustment without requiring an expensive 10 turn pot.
Make the main current carrying connections to the power resistor. Tap off of this go to the meter. That way, it is less likely that a bad connection can result in the shunt opening - which would fry your meter in an instant!
Calibrate this setup using a DC power supply and known accurate ammeter.
With a dual trace scope, for example, set up the vertical channels to be A-B (A, invert B).
A dedicated panel meter is best for this as well. Obtain a panel meter with a full scale sensitivity of 75 to 100 V or add an appropriate series resistor to a current (e.g., 100 uA full scale) meter. Make sure the resistor(s) can handle the maximum voltage!
+--+ M1
R1 | v R2 + +----------+ -
+ o------/\/\----+-/\/\--------| 0-100 uA |----------o -
940K 100K +----------+
Calibrate 100 V Full Scale
An isolation transformer is highly desirable for personal safety and to protect your (grounded) test equipment.
Given that this is unrealistic, make sure you understand the safety guidelines provided in the document: Safety Guidelines for High Voltage and/or Line Powered Equipment - AND FOLLOW THEM! Minimize the amount of probing done under these conditions and make connections only with power off (and large capacitors discharged!).
(From: Steve Roberts (osteven@akrobiz.com)).
Where there is no robust current regulator, for initial testing it is wise to start at 7 or 8 Ohms and work down, even with the pi section CLC or CRC filter as these discharges do possess a negative runaway characteristic despite what the literature says. For some reason it always seems to need a 2 to 4 ohm offset above the calculated value or it will run away.
They also need a minimum current of about 3.5 amps to sustain the discharge with a new tube and about 4.35 A as the tube grows older, this was just measured in my shop with a new tube versus a tube with 2000 hours on it. The new one (an Omnichrome 532 with a buck converter) dropped out on line voltage dips when it came from the factory set for a 3.25 A lower limit. This was on 118.2 V AC.
Therefore when firing up a 'heater' (space heater ballast) based supply, you often have to lower the resistance a little at a time to find the minimum stable current point. It is better to start a high resistance and work down. Of course, you will have a permanent current monitor in the system!
Also see the sections: Measurements of Current and Voltage in Ar/Kr Ion Laser Power Supplies and Testing with a Dummy Load.
It will be necessary to power the logic and control circuits separately for this test so that their supply voltage is constant.
Provide wired-in monitoring of BOTH load (tube) current AND regulator voltage drop. (See the section: Measurements of Current and Voltage in Ar/Kr Ion Laser Power Supplies.)
Select the load rating, with the Variac at 0, power on the main supply. Bring up the voltage slowly.
Needless to say, when designing such a power supply and selecting components, err on the side of being conservative. Select parts to run at much less than their rated voltage, current, or power (maximum stress of 1/2 the part's rating isn't too bad a rule-of-thumb). This is especially important for devices that fail in a sudden catastrophic manner like power semiconductors!
Where a high power regulator uses a large series-parallel combination of power transistors, if one shorts, it may overstress others. If there is inadequate protection, multiple devices will fail in rapid succession until the entire regulator behaves like a blob of solder taking other parts with it. Even components that still appear to function may have suffered permanent damage during the overload.
There are also some comments on the repair of specific power supply models in the chapter: Complete Ar/Kr Ion Laser Power Supply Schematics.
For much more information on the servicing of these types of devices, see the following (as appropriate for your power supply):
Before beginning a lengthy troubleshooting session, check the following:
WARNING: Do not put your eyeball (or any other part of you!) near the tube. Aside from the high voltage, there is considerable UV which isn't any good for organic matter either!
If under light control, the current will likely be pegged at the maximum (e.g., 10 A) attempting to get a proper power beam.
Check the mirror alignment and/or clean and/or realign the resonator as appropriate. See the sections: Checking and Correcting Mirror Alignment of Internal Mirror Laser Tubes or Argon/Krypton Ion Laser Cleaning and Alignment Techniques (external mirror tubes) depending on the type of laser tube in your system.
WARNING: Some or all of these power supplies are line connected - take extreme care with measurements! See the section: SAFETY when Dealing with Ar/Kr Ion Laser Power Supplies.
If there is no evidence of the tick-tick-tick sound, check the (boost) supply supply directly at the igniter circuit. It is also possible to test the output of the igniter by disconnecting it from the tube (with power off and everything discharged!) and checking that it will arc 1/3" to 1/2" to a suitable ground point.
Where the power supply and igniter check out, the tube pressure may be too high (from non-use) or the tube may be misbehaving just because it felt like it - but this may be reversible. It may be possible to the tube to start using an Oudin coil and then run it for several hours to drive down the pressure. See the section: Hard-to-Start Ar/Kr Ion Tubes - Outgassing and Keeping Your Laser Healthy.
I cannot stress enough the need to have a curve tracer around, even a home-built one, for checking pass-bank transistors in-circuit. However, the following procedure using only a multimeter will also work for identifying bad transistors in the Lexel-88 (or most any other) pass-bank in-circuit (where all the collectors are tied together) is:
Having gotten that out of the way, here are two circuits that should be adequate for a typical small air-cooled Ar/Kr ion tube.
+-------------+ + R1 R2
Vin+ o----| |------/\/\-----+-----+---------/\/\-------+
| HV DC Power | 400K | | 140 |
| Supply | 10W | | 10W |Tube+
| 2 KV, 10 mA | - | | .-|-.
Vin- o----| |---+ | / | | |
+-------------+ | C1 _|_ \ R3 | |
| .25uF --- / 10M | | LT1
| 2,500V | \ | |
| | | | |
| | | ||Z.|
| | | o - Test + o '+-+'
| | | | Rs | F1| |F2
NC o-+ T2 +-----------+-----+---+---/\/\---+ | |
)|| _|_ 1 | | |
AC o----------+ || - | | |
)|| | | |
Variac )<--------------+ T1 | | |
0-140V )|| )|| +-----------------|----+ |
1A )|| Filament )||( Tube- | |
)|| Transformer )|| +-----------------+ |
+--+ 3VCT,15A )||( |
| )|| +------------------------+
AC o-------+-------------------+
Running this at a few pulses per second for a reasonable length of time (i.e., not for days on end) should result in no significant damage to the tube or shorten its life by any detectable amount. You shouldn't need to run it this way for very long in any case - just don't think that this setup can be used in place of a REAL power supply!
As long as the peak current exceeds the tube's lasing threshold, there should be visible flashes of laser light from its OC (output coupler) end if it is working and aligned correctly.
WARNING: This circuit is still dangerous - just less so than a full blown ion laser power supply. The anode of the tube (including the mirror mount at that end!) will have a voltage of up to 1.5 KV with respect to ground (for this example). While the amount of energy stored in C1 is fairly small - less than .5 J (W-s), it can still be lethal under the wrong conditions. The HV power supply itself can deliver up to 5 mA through R1. Either of these are at least enough to evoke a reflex response which may ruin your whole day even they do not kill you. Take care.
Note: I show the entire setup earth grounded including the tube cooling fins and support structure. This makes it safe to touch everything BUT the tube anode (and of course, the HV power supply). Floating the entire affair is also possible but most of the same problems exist since portions of the tube will still be at the negative potential of the power supply and, if you use the scope monitor points across Rs, will be grounded through the scope (unless you isolate that as well - which is not recommended).
It may also be possible to use this approach for starting small to medium size tubes since it provides a 'boost' voltage like that used by the igniter of the ALC-60X/Omni-532, SG-IT1, and SG-IL1. See the section: Pulsed Operation of an Ar/Kr Ion Tube.
What this design provides is two power supplies driven from a single 650 VRMS center-tapped transformer (T3). Many other approaches for the power sources are possible. See the chapter: HeNe Laser Power Supplies for ideas.
Note that D7 can be built from 4, 1000 V, 2.5 A diodes in series since the single cycle (pulse) rating for these is much higher than the approximately 10 A (15 A without the regulator) peak that is required.
The (optional) constant current regulator allows the tube current to be set at a high but safe value. If a simple resistor is used, either the current would be lower than desired for most of the discharge, or higher than the maximum tube specs for some portion of it. If you don't use a regulator, change R2 to 33 ohms at 10 W (for 12 A peak).
R4 D3
+---/\/\---|>|---+----+----------------+
| 10K 1KV | | |
| 10W C3 _|_ / R5 |
| 75uF --- \ 220K |
| 350V | / +-------------+
| | | | Constant |
| +----+ | Current |
| | | | Regulator |
| C4 _|_ / | (Optional) |
| 75uF --- \ R6 +-------------+
| 350V | / 220K |
| | | D5 |
| +----+ +---|<|---+
| _|_ | 3KV
| - | 2.5A
| |
T3 R1 | C1 D1 | R2
+--/\/\---|---||---+---|>|---+----+----+-------/\/\-----+
||( 2M | .01uF | 3KV | | 5 |
||( | 3KV | | | 10W |Tube+
AC o--+ ||( 325V | | | | .-|-.
)||( | | C2 _|_ / | |
)||( | | .01uF --- \ R3 | |
)|| +---------+ | 3KV | / 20M | | LT1
)||( | | \ | |
)||( | D2 | | | |
AC o--+ ||( 325V +---|<|---+ | ||Z.|
||( 3KV | | o - Test + o '+-+'
||( | | | Rs | F1| |F2
+----------------------------+----+----+---/\/\---+ | |
650VCT 1 | | |
50mA NC o-+ T2 | | |
)|| | | |
AC o----------+ || | | |
)|| | | |
Variac )<---------------+ T1 | | |
0-140V )|| )|| +--------|----+ |
1A )|| Filament )||( Tube- | |
)|| Transformer )|| +--------+ |
+--+ 3VCT,15A )||( |
| )|| +---------------+
AC o-------+--------------------+
Setup and operation is similar to that described in the section: Ar/Kr Ion
Tube Pulse Test Circuit 1. Adjust T2 to obtain the proper filament voltage
for your tube and modify the value of R1 to vary the pulse rate.
The remaining details are left as an exercise for the student! A switchmode buck converter will be needed for the optional regulator unless you have a bank of really high power transistors gathering dust in your junk box. :-) The problem with using a linear regulator is the peak power dissipation and keeping inside the SOA (Safe Operating Region) for the transistor(s). A common BUT12A would handle the current and voltage individually for this example but not the peak 4,000 WATTs - 400 V AND 10 A at the same time!
WARNING: Take care as C3 and C4 can pack quite a wallop - especially once you increase their size - as I know you will. ;-) And, both supplies can deliver dangerous levels of current continuously even without the capacitors!
An alternative which may work for some small tubes like the Cyonics (those which will start without help from a boost source) is to use a line powered (non-isolated or 1:1 isolation transformer) supply for the pulse current source followed by an (optional) linear or switchmode regulator.
Without the regulator, it would look like the following:
R1 D1 R2
+2 KVDC o----/\/\-----------+----|>|-----/\/\---+--------+
100K | 3KV 100 | |Tube+
C1 _|_+ 1A 10W | .-|-.
1uF --- | | | |
3KV | - | | |
R3 | D2 R4 | | |
+150 VDC o----/\/\-----+-----|----|>|-----/\/\---+ | | LT1
100,25W | | 3KV 4 | |
C2 _|_ + | 6A 10W | |
500uF --- | | |
200V | | ||Z.|
| - | '+-+'
DC RET o-------------+-----+----------------------+ F1| |F2
| | |
NC o-+ T2 | | |
)|| | | |
AC o----------+ || | | |
)|| | | |
Variac )<---------------+ T1 | | |
0-140V )|| )|| +--------|----+ |
1A )|| Filament )||( Tube- | |
)|| Transformer )|| +--------+ |
+--+ 3VCT,15A )||( |
| )|| +---------------+
AC o-------+--------------------+
Details of this, too, are left as a exercise for the student!
A 600 VCT power transformer (T2) charges the energy storage capacitor (C1) to approximately 425 VDC and also drives the parasitic voltage multiplier to generate an additional starting voltage of up to more than 2,500 VDC. When the Ar/Kr ion tube starts, C1 discharges through D9 with a current limited to about 10 A by R3. The uF value of C1 may be changed to provide the desired discharge energy. Adjust the values of R2 and/or C3 to assure that C1 charges in a shorter time than it takes for the HV to build up to the point at which the tube starts.
My first version of this circuit was built as an all-on to a 30 year old home-brew tube-type bench power supply (remember the 5U4GB rectifier tube?). I never thought I would ever find a use for that again but it did have all the connections required to attach the output and voltage multiplier conveniently located on front panel binding posts!
C2 C3 C4
+------||-------+------||-------+------||-------+
| D3 | D4 D5 | D6 D7 | D8
R3 / +--|>|--+--|>|--+--|>|--+--|>|--+--|>|--+--|>|--+
1M \ | C5 | C6 | C7 | R4
/ +------||-------+------||-------+------||-----+-+--/\/\--+
| D1 | R1 D9 R5 | 100K |
T2 +--+--|>|--+-+---/\/\-------+----+--------|>|------/\/\--|----------+
||( | 1K | | 3KV 30 | |
||( | 10W C1 +_|_ / R2 2.5A 10W _|_ C3 |Tube+
||( 300V | 10uF --- \ 470K --- .01uF .-|-.
||( | 450V - | / 1W o - Test + o | 5KV | | |
||( | | | | Rs | | | |
|| +------------|--------------+----+-------+---/\/\---+----+ | |
||( | 1 | | | LT1
||( | T2: 600VCT, 50mA | | |
||( 300V | D1-D8: 1N4007 | | |
||( | C2-C7: .01uF, 1.2KV | ||Z.|
||( D2 | | '+-+'
+-----|>|----+ AC o--------+ T1 | F1| |F2
)|| +-----------|---------+ |
(Ac input and Filament )||( Tube- | |
T2 primary Supply )|| +-----------+ |
not shown) )||( |
)|| +-----------------------+
AC o--------+
Like the other pulse supplies, this can also be used as a starter for some
small ion tubes. All that is needed is a high voltage high current blocking
diode between the ion tube anode and the DC+ output of a the normal ion laser
power supply.