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switch help Answered

I'm doing a school contest with a car which requires a toggle switch. I'm gtoing to use a dcd to dc converter to give me an edge. The only problem is that it needs to be a momentary switch. whenever you push the switch down it goes on. Whenever you push it down again it turns off. Any idea for a circuit so that a spdt (3 pins) toggle switch will act like a momentary switch each time it's flicked for a time like a second?

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Patrick Pending

12 years ago

I understand what you want to do, but It would help if you described exactly what it would be switching. Imagine that you were using a momentary switch - how would you wire it to your circuit to make it operate? Cheers, Pat. Pending

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guyfrom7upPatrick Pending

Reply 12 years ago

this thing will be operating a dc to dc converter so I can give my motor more volts and amps so I go really fast. To turn on and off the integrated boost chip a pulse is required, which would normally be a pushbutton momentary switch.

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Patrick Pendingguyfrom7up

Reply 12 years ago

To turn on and off the integrated boost chip a pulse is required,

This is what I am getting at. Can you describe what type of pulse is required +ve or -ve going, edge triggered, TTL , etc., and also what duration, voltage, and current is required?

Cheers,

Pat. Pending

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guyfrom7upPatrick Pending

Reply 12 years ago

i just have to connect one pin to Vin so I think I'm probably going to use the circuit nachomahma said and use a relay at the end of it.

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guyfrom7up

12 years ago

I'm sorry, let me say this in a more clear, basic way. On the toggle switch there's 3 pins (middle is common) . This is a normal toggle switch. I want a circuit so that everytime you flick it over it turns a relay or something like that on for something like 1 second, no matter which way you flick the switch it'll turn something on like a relay for 1 second, but the switch is still in the same spot. So in a way it would be like holding a momentary switch down for a second..

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NachoMahmaguyfrom7up

Reply 12 years ago

. Ah. This (it's a PDF) should help or try searching for one-shot electronic.

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guyfrom7upNachoMahma

Reply 12 years ago

thank you sooo much, that is like exactly what I wanted. Do you know how to adjust the time of the pulse? TIME = APPROX. RC I don't know what that means. resistor in ohms times capacitor in farads equals time in... second?

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NachoMahmaguyfrom7up

Reply 12 years ago

. I'm not sure. Maybe someone else can fill in the details.

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GoodhartGoodhart

Reply 12 years ago

Sorry, I goofed again in linking to a post when this should have been a separate entry (maybe)

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NachoMahma

12 years ago

. I'm confused. Do you want a toggle handle with spring return that switches (ratchets) whenever you push the handle?

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Goodhart

12 years ago

IF I understand you correctly, there are switches made that do this, both button and regular toggle switches. But if you need a circuit, a simple flipflop should suffice. Since I don't know power constraints, for low power circuits a CMOS 4013B should do.

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guyfrom7upGoodhart

Reply 12 years ago

no, the problem is that it MUST be toggle, when I need a momentary switch that have clear on and off markings