I built the circuit on a breadboard. Using a bench power supply for power source.
The capacitance values are as shown in the schematic, all ceramic capacitors. When I put a load resistor on pin 3 to ground, the circuit works as I described. It goes high for a short time, then it goes to zero volts. However, when I remove power from the circuit, the voltage at pin 3 goes high again and slowly drains down to zero.
My suspicion is that because pin 4 is tied to VCC, it leaves pin 3 in an "on" state and whatever is causing it to clamp down to zero after power on is simply...
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I built this circuit
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And indeed when I measure across the 10k resistor, I get 5 volts for a short time, and then it goes to 0. However, when I remove power from the circuit altogether, the voltage across the 10k goes close to 5 volts and then slowly dissipates ... it takes about 5 seconds for this to happen. How can I make sure that the 10k stays at 0 volts when I cut power to the circuit?I built this circuit
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Well, the idea is that as soon as voltage is applied, the transistor goes into saturation but only for about 1 second ... maybe 2 or anywhere in between, but then after that time, the transistor shuts off even though power is still applied. Also, I calculated the values of R1 and C1 using t = RC where 33k times 47ยต = appx 1.55 seconds....
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Anyone have experience with an RC driven temporary "ON" transistor switch?
Hello,
The idea is to use a transistor to activate a latching relay once a voltage is applied but to prevent a constant voltage from being applied to the relay coil, I thought it might be a good idea if it were possible to make sure that the voltage applied to the coil is temporary even though the source voltage could be "ON" for long periods of time.
This is the circuit that I came up with. I have not tested it yet because I don't have the relay yet, though I am looking for anyone who might have experience with this kind of a setup to hopefully offer some advice,...
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