Hey everyone,
As part of a larger project I need a circuit that functions like a SPDT relay, but also need an 'OFF' position.
It is a rather complex application but, to explain it simply, I have a switch that has two solenoids attached to it. One solenoid moves it 'on' and the other moves it 'off'. It will latch in either position when power is removed. The solenoids are only rated for a very short duty cycle (~5%) so I will be operating them with pulses. I think I've got the SPDT portion figured out from some other posts, but I'm not sure how best to do the 'pulse'. I'm thinking maybe the yellow box might work?
The thought is that I can briefly close the switch (relay) to pulse power and, when its open, the 10k resistor will keep the emitters of all my PNP transistors (120 of them since 60 switches) from floating? But I'm concerned if I will cause damage to the transistors pulsing power like this. Any comments or other ideas would be awesome.
FYI, each solenoid pulls about 600 mA (and I have 60 'switches' to control, so that is 36 amps, so I will be doing the 'pulse' with a physical relay.)
Thanks!
aapitten
As part of a larger project I need a circuit that functions like a SPDT relay, but also need an 'OFF' position.
It is a rather complex application but, to explain it simply, I have a switch that has two solenoids attached to it. One solenoid moves it 'on' and the other moves it 'off'. It will latch in either position when power is removed. The solenoids are only rated for a very short duty cycle (~5%) so I will be operating them with pulses. I think I've got the SPDT portion figured out from some other posts, but I'm not sure how best to do the 'pulse'. I'm thinking maybe the yellow box might work?
The thought is that I can briefly close the switch (relay) to pulse power and, when its open, the 10k resistor will keep the emitters of all my PNP transistors (120 of them since 60 switches) from floating? But I'm concerned if I will cause damage to the transistors pulsing power like this. Any comments or other ideas would be awesome.
FYI, each solenoid pulls about 600 mA (and I have 60 'switches' to control, so that is 36 amps, so I will be doing the 'pulse' with a physical relay.)
Thanks!
aapitten