Quote:
Originally Posted by LieutenantCracker
I want to make a " momentary switch (button)" work as continuus-current switch-- in the same way that a typical rear-window defroster button works, in a car; INSTEAD of using a toggle, rocker, or clicking-pushbutton, continuous - current switch.
Obviously there'd be a relay involved but, how would I wire a controller, such as this?
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What you're looking for is a latching relay circuit. If you're not restricted to the use of just one switch, and if you have both a momentary normally-open and a normally-closed switch available then the latching circuit on
this page would do the job.
A good selection of basic relay circuits on
this page, including two latching circuits using a single momentary switch. The price you pay for using the one switch though is that it requires multiple relays - four in total in the first circuit plus two diodes, or the second circuit dispenses with the diodes but requires a fifth relay. That's all a bit clumsy and bulky though and would need careful construction if it was to be reliable in operation.
There are latching relays available but I think they require the use of two switches. There will be other solutions too but they're likely to require the addition of a few components - resistors, capacitors, diodes, maybe a transistor or two for coil switching purposes, and I don't know if you would want to go to that level of complexity. Somewhere in the house I have a textbook containing nothing but relay circuits - delayed-on, delayed-off, etc., and that's sure to include a latching circuit or two but I can't find it right now, probably because I haven't used a relay in a circuit in over a decade. A Google search containing the words latching relay circuit would probably lead you to some other solutions.