I have a momentary switch. When I press it, I want to switch something on (light bulb) and have it stay on even though momentary switch was released. maybe 500 mA draw.
When I press it again, it turns the light bulb off. How do I do this? This is in a 12VDC circuit.
Will in the end, I need a circuit to do this. But I do want to learn. What I asked for is actually only part of the functionality, but I see it as a building block to start with and was hoping I might figure the rest out on my own.
Well a push-on push-off switch isn't really momentary. It feels like a momentary switch, but doesn't function like one. I have to use a momentary switch, no option because or existing hardware.
Well a push-on push-off switch isn't really momentary. It feels like a momentary switch, but doesn't function like one. I have to use a momentary switch, no option because of existing hardware.
No, but maybe I'll have a crack at it when I get some time. Meanwhile, I've put together this scan from my original source: "Elektor 302 Circuits", ~1985
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which explains its working.
And I'm pretty sure I breadboarded it successfully a decade or two ago.
Okay, thanks for all the replies. Sorry to change things up on you...but like I said early on, this is a learning experience for me. It has occured to me that I don't want to worry about contact bounce and that in reality, this will fit my application much better if there are 2 momentary switches. pressing one of them turns the system on and pressing the other turns the system off. i can probably adapt this setup somehow from some of the provided circuits, so I will look into it. this might actually simplify the circuit too i would think. THANKS!
Ken Moffett wrote in news:Xns96EE4ED95F5AEqwerty@24.94.170.94:
I looked back at the circuit again and noted something they had left out. The relay in their circuit was a 12vdc for the 24v supply. So for a 12v supply you would choose a 5vdc or 6vdc DPDT relay. The resistance of R1, R2, and relay's coil would all be approximately equal.
How much simpler can you get than the circuits posted? Have you tried any of them yet?
Hey, how about an even simpler approach: a single toggle switch? No buttons, no electronics. AC or DC power supply in at one side, and out of the other to whatever you want to control. Its explanation is as follows: when you switch it one way, the circuit is powered on. When you switch it the other way, the circuit is powered off again. Very reliable, parts easily obtained. What's more, it has another advantage over a button-based approach: the status of the circuit is always visibly obvious (providing the two switch positions have been marked accordingly, e.g. 'On' and 'Off' or whatever.) This advantage over buttons applies even if the load has failed somehow (lamp filament burned out, motor stalled, etc).
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