Re: TI-H: Circuit/component help
[Prev][Next][Index][Thread]
Re: TI-H: Circuit/component help
>I don't remember exactly how the flip-flops work, but they come in a lot
>of packages (DIP14 for example) and can be set up such that the first time
>a signal goes active the device will latch ON (or OFF, if you prefer) and
>will ignore all additional signals until a reset happens. I haven't done
>that for a while, though, so I don't remember exactly how to go about
>doing it. A drawback to this is that you must have a nice clean 5 vdc
>supply for the flip-flop, and then you'll need interface stuff for
>whatever circuitry you want it to control.
You wouldn't need too much interface stuff... Just a transistor depending
on the load of the alarm or what ever he is going to connect to the trip
thing.
If you have the Radio Shack electronics book, there is a circut example
that is exactly what Greg said. I think its in the IC section. Havn't
read it in a long time.
Grant
>The SCR method should be pretty easy: SCR stands for Silicon Controlled
>Rectifier. It's basically a diode, but it's got a gate in addition to the
>anode and cathode. When a signal arrives at the gate, it allows current to
>pass through the diode. Current will continue to flow, even after removal
>of the activation signal, until the current is interrupted. So you set up
>the circuit to give a pulse of whatever length to the gate of the SCR, and
>put a normally closed momentary switch in series with the diode. When the
>activation signal goes up, current flows. It continues to flow until the
>SPST(n.o.) switch gets depressed.
>
>
>--
>Greg Hill
>greg-hill@bigfoot.com
>www.comports.com/link
Follow-Ups:
References: