C
Conan Kelly
- Jan 1, 1970
- 0
Hello all,
My background is not in electronics. It is in car stereo & security. So please dumb-it-down for me.
What is the minimum voltage required to energize the coil of a standard 12 VDC relay? How can I wire 2 relays with resistors so
that the output line will be switched off when the voltage drops below 9.6 Volts?
I think that I might have a diagram on how to wire 2 relays and a momentary push-button switch (and maybe diodes) so that each push
of the button toggles the output line between OFF and ON. I was thinking that there is probably some similar way of wiring 2 relays
with resistors to accomplish what I'm trying to do.
The reason that I'm trying to do this is because I have a Makita 12V cordless drill. I gutted an old Makita battery charger and
wired it so I could drain the battery or power small 12V devices off of the drill battery. I read somewhere that the ideal
discharge for NiCad batteries is 1.2 V per cell before recharging. (I'm guessing that there are 8 cells in a Makita 12V
battery--12V / 1.5V per cell = 8 cells--8 cells * 1.2V per cell = 9.6 V ideal discharge) Right now, it is wired directly to the
battery so the thing can be completely discharged if a cell phone cigarette lighter charger is left on it too long. I was hoping to
find a way to use relays and resistors and what-not to get my contraption to shut off when it reaches the target voltage.
My background is not in electronics. It is in car stereo & security. So please dumb-it-down for me.
What is the minimum voltage required to energize the coil of a standard 12 VDC relay? How can I wire 2 relays with resistors so
that the output line will be switched off when the voltage drops below 9.6 Volts?
I think that I might have a diagram on how to wire 2 relays and a momentary push-button switch (and maybe diodes) so that each push
of the button toggles the output line between OFF and ON. I was thinking that there is probably some similar way of wiring 2 relays
with resistors to accomplish what I'm trying to do.
The reason that I'm trying to do this is because I have a Makita 12V cordless drill. I gutted an old Makita battery charger and
wired it so I could drain the battery or power small 12V devices off of the drill battery. I read somewhere that the ideal
discharge for NiCad batteries is 1.2 V per cell before recharging. (I'm guessing that there are 8 cells in a Makita 12V
battery--12V / 1.5V per cell = 8 cells--8 cells * 1.2V per cell = 9.6 V ideal discharge) Right now, it is wired directly to the
battery so the thing can be completely discharged if a cell phone cigarette lighter charger is left on it too long. I was hoping to
find a way to use relays and resistors and what-not to get my contraption to shut off when it reaches the target voltage.