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Reply With QuoteThis would be great... but what are the gates? Simple AND gates or what? and the edge triggered circuit?
I think the best way to find out is to build it and try it. I'll be the guinea pig if I can get some part numbers.
Jon
the 5 volts will be the same 5 volts used as the 5vsb and the switch is the accesory line.
when you turn on the car the cap charges and sets off the and gate which turns on the edge triggered circuit which pulses the tranny and flicks the relay on and off
when you turn off the car the cap discharges and the and gate buffer turns off and the edge triggered circuit pulsees the relay again.
the relay is connected to the 2 mobo power switch pins
if anyone has a better circuit for turning the car on after the car has been started (15 seconds ish like this one) and turning it off about the same time after its been turned off id be interested
note in this one the delay is stopped each time the switch goes off or on...if you know what i mean.
im not sure if i need the tranny but i put it in for safteys sake
This would be great... but what are the gates? Simple AND gates or what? and the edge triggered circuit?
I think the best way to find out is to build it and try it. I'll be the guinea pig if I can get some part numbers.
Jon
4 of the gates are and gates adn the last one is a xor gate
the adge triggered circuit is the 2 ands on the input of the xor...because there is a delay between a gate getting an imput and it sending it to the output this means that one leg of the xor is delayed fromthe other that gets its signal straight away...so you get a pulse.. the only thing that might not work in this is the pulse out of the end is too short and the relay wont have a chance to trigger. im not sure what kinda time they take cos ive never really looked at one in any great detail...could just slap a monostable on the end there but it justs makes the circuit larger.
4081 for the 4 ANDS
4070 for the xor (you get 4 of them but you could just tie one of the pins to logic 1 on the remaining three and use them as logic buffers in the edge triggered circuit giving a longer delay...although it still might ot be enough)
a wieny tranny and a wieny relay will do the job aswell.
Your pulse is going to be on the order of nanoseconds..
What are you pulsing again? Why do you need a relay? the input to the motherboard is a simple gate too. It is just pulled up and debounced.
Jeff
MPEGBOX - Plexiglass Computer
www.mpegbox.com
How is the "switch" connected to the ignition? Do you have some extra wires that are isolated that you can get to on the ignition switch?
MPEGBOX - Plexiglass Computer
www.mpegbox.com
If you want to look at the pulser that I made that uses 2 inverters, check out this;
B would be your input, C would be the output.
http://skylab.org/~chugga/mpegbox/po...owerdelay2.GIF
Put your same delay on the input to delay 15 seconds.
MPEGBOX - Plexiglass Computer
www.mpegbox.com
the switch IS the ignition...well kinda...its the accesory line..you know the one that comes on when you start the car.
if the on thing is a logic gate then surely i can just put in the output of the xor gate?
what type of gates is the soft on compatible with...ttl or cmos? [edit] having a look at your diagram have you used a tranny over the 2 pwr switch pins? [/edit]
the relay was just to simulate a switch on the on button
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