LASER Power Supply

If you have ever worked with lasers, you know how fun and interesting it can be, you also know how expensive it can be. The high voltage power supplies for the laser tubes are often more expensive then the tubes themselves. This supply can be built with commmon parts, most of which you probably already have in your junk box. The secret is the transformer used. It is a common 9V 1A unit, connected backwards for step up.

Parts



R1(1)10 Ohm 10W Or Greater Resistor
R2(1)Ballast Resistor, See "Notes"
D1, D2, D3(3)1N4007 Silicon Diode
C1, C2, C3(3)0.1 uF 2000V Capacitor
T1(1)9V 1A Transformer
S1(1)115V 2A SPST Switch
MISC(1)Case, Wire, Binding Posts (for output), Line Cord


Notes

1. T1 is an ordinary 9V 1A transformer connected backwards for step up.
2. R1 MUST be installed on a LARGE heatsink. A good heatsink is the metal case the supply is built in.
3. R2 Protects the laser tube from excess current. It should be soldered directly to the anode terminal on the tube. To find R2, start with a 500K 10W resistor and work down until the tube lights and remains stable.
4. If you have trouble with the tube not starting easily, use a longer anode lead that is wrapped around the tube.
5. Depending on the transformer you use, the circuit may or may not work. I cannot guarantee the operation of this circuit. Build at your own risk. Some transformers contain very few secondary windings which will quickly saturate the core and basically act like a direct short. The more secondary windings (that is, primary in this circuit) the better.

LASER Transmitter/Receiver

This set of two circuits from the basis for a very simple light wave transmitter. A LASER beam is modulated and then aimed at a receiver that demodulates the signal and then presents the information (voice, data, etc..). The whole thing is very easy to build and requires no specialized parts execpt for the LASER itself. LASERs are available from MWK Industries.

Schematic Of Transmitter

Schematic Of Receiver

Parts
C!,C2               2             0.1uF ceramic disc capacitor
C3                    1             100uF 25v electrolytic capacitor
R1                    1             100k ohm 1/4w resistor
R2                    1             1M ohm 1/4 resistor
R3                    1             10k pot
Q1                    1              NPN phototransistor
U1                    1              741 op amp
U2                    1              LM386 audio amp
SPKR1            1              8ohm speaker
T1                     1             8ohm:2k audio transformer
MISC                1             wire,board,knob for r3,laser tube and power supply


Note

1. In the transmitter schematic, no ballast resistor is shown because most small LASER power supplies already have one built in. Yours may differ, and a resistor may be needed.
2. The receiver should be kept away from bright lights. You may want to put a piece of wax paper in front of Q1 to keep the LASER from swamping it.
3. In order to get any decent amount of modulation, you may need to drive T1 with more then a watt.
4. The circuit can be made to transmit computer data with the use of two modem chips.

source