|
The blue and green signals are the 2 throws of the relay and the orange is the pole, the 1P1T switch sends a high or low signal to open or close the relay :)
Ideally the transistors should be P JFETs because their drain and sources are interchangeable more often than not, so the switch is bipolar like a relay.
The concept is that the transistors are alternatively saturated and at cut off so one constricts the input signal while the other allows it to pass freely. Could be made with complementary parts, one N and the other a P, but wanted to try using both Ns and inverting the turn on signal for one of them. The inversion could be made with a 3rd transistor and a resistor on its drain (inverting amp), at its gate the input signal to activate the relay, and from its drain the inverted signal to open or close the 2nd transistor. However, I wanted to give the op-amp comparator with hysteresis (schmitt inverting trigger) a shot since I just learnt about them. The circuit seems to work fine except that the blue signal bleeds a little to the orange side when it's supposed to be completely cut off.
|
