WARNING!
The circuitry described herein deals with potentially Lethal High Voltages, it
is strongly recommended that an isolation transformer be used to power this
device. Please use a little common sense, and if in doubt do not do it. I take
no responsibility for any death, damages, or injury incurred by anyone. If you
are not familiar with electronics, are uncertain of safe operating practices or
are lacking in common sense, please
leave now!
| C1 = 220�f 200 working
volt C2 = 47�f 35Volt Electrolytic C3 = .1�f 50V Monolithic C4 = 1�f 200 working volt D1-D4 = 200Volt 1Amp Bridge Rectifier D5 = 1N4744 15Volt 1 Watt Zener Diode R1 = 4700 Ohm 10 Watt R2 = 4700 Ohm 1/4 Watt R3 = 10 K Ohm Potentiometer R4 = 1000 Ohm 1/4 Watt R5 = 10 M Ohm 1/4 Watt Q1 = 2SC1308 (NPN 200V 5W or better) U1 = 741 OP Amp S1 = 125VAC .3 Amp Toggle Switch F1 = 1/16 Amp 125VAC Fuse Holder for above I1 = Panel mount Neon w/resistor T1 = 120Volt 60ma. 1:1 Isolation Type misc. Case, perfboard, 3 Wire Line Cord |
T.V. repair RS 272-1027 RS 272-109 RS 272-1055 RS 276-1161 RS 276-564 T.V. repair RS 271-1330 RS 271-1715 RS 271-1321 RS 271-1365 RS 276-2055 RS 276-007 RS 275-645 RS 270-1044 RS 270-362 RS 272-712 Triad RS 276-148 |
As shown this device has a range of 0 to 10ma of constant current (current remains constant regardless of load) for loads from Zero ohms up to 16K ohms the output voltage will vary to maintain the current at the level set by R3 up to about 160 DC Volts of output, use caution, even when the switch is off there can be enough charge on C4 to cause burns. (it takes about 10 seconds for the charge on C4 to bleed off through R5 to a safe level)
Changing the value of R4 will change the Max Current, for
example 10K will give a range of 0 to 1ma.
But be aware that decreasing R4's resistance will require increasing it's
wattage and the wattage of Q1, for example R4=470 ohm 1/2 Watt will double the
dissipation of Q1 as well, and give a range of 0 to 21ma.
