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VOLTAGE ACTIVATED SWITCH!

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JATEU_01

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Somewhat of a novice here lol.

Thanks for your help.

can anyone help me with a peoblem, im looking for a circuit that will detect a 10-14v variable voltage and then activate a switch on/off.

thanks for your help.

my emails are as below
 
could you be a littel bit more specific pease.

when do you want the switch to go on/0ff??
what will it be switching? AC/DC? voltage? current?

a relay would be one option. but youd would have to have a sutable current to drive it.
if you want to trigger AC you could always use a TRIAC.
 
SPEC

this circuit will be controling a 12v relay, the power supply is 11-13v. i want to be able to use this circuit as a auto switch off. that when a 10-14v voltage id detected the circuit wll switch off the relay.


thank you for your help....
 
Here's an example, you need to program the PIC with correct code...
 

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Do you know PIC's ? This is an ideal task for PIC, really cheap and simple.
:shock:

Why use a PIC it woudl just be a wast of its processing power! totaly pointless. of course you could use a PIC if you want, it will do the job. but u'll have to get a programer and learn the programing language.

an easier way would be to use a simple comparitor circuit, use an op-amp.
when the input voltage goes higher than 10V, the output goes high (or low depending on how you wire it) and all is good. :D
 
Misterbenn said:
Do you know PIC's ? This is an ideal task for PIC, really cheap and simple.
:shock:

Why use a PIC it woudl just be a wast of its processing power! totaly pointless. of course you could use a PIC if you want, it will do the job. but u'll have to get a programer and learn the programing language.

an easier way would be to use a simple comparitor circuit, use an op-amp.
when the input voltage goes higher than 10V, the output goes high (or low depending on how you wire it) and all is good. :D
Well it depends, I know PICs and it is easier for me to do it with it. Also, using PIC you can add more features to your design, such as Acustic or LED signalisation or controlling of more inputs, everythink using one 8pin device!
 
You can use a small relay, a reed relay for example, with normally closed contacts as the 10 to 1V detector. (A 12V relay will operate on this range.)
When it is energised its contacts open and switch off the other relay.
 

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Misterbenn said:
Do you know PIC's ? This is an ideal task for PIC, really cheap and simple.
:shock:

Why use a PIC it woudl just be a wast of its processing power! totaly pointless. of course you could use a PIC if you want, it will do the job. but u'll have to get a programer and learn the programing language.

an easier way would be to use a simple comparitor circuit, use an op-amp.
when the input voltage goes higher than 10V, the output goes high (or low depending on how you wire it) and all is good. :D

Because a PIC will be able to latch. If you do this relay to switch off a load, it will switch on/off, on/off, on/off endlessly.
You could also make the relay coil's circuit powered from the contacts, but then you'd need a button to turn it on in the first place.

The coil itself is not very useful as a voltage detector, though it does have good latching behavior. Where it turns on or off is not well specified and varies with temp & vibration.
 
the op-amp coulb be folowed by a simple latching circuit.

i think people are to ready to use PICs, they are very good, and beat hardware hands down in most situations, not all the time tho.
sometimes hardware is just simpler and quicker.

personaly in this situation as i understand it i would use hardware, its a simple function that needs to be done. also the original task didn't involve any "Acustic or LED signalisation".

just a point, dont always jump straight to PICs
 
Misterbenn said:
the op-amp coulb be folowed by a simple latching circuit.

i think people are to ready to use PICs, they are very good, and beat hardware hands down in most situations, not all the time tho.
sometimes hardware is just simpler and quicker.

personaly in this situation as i understand it i would use hardware, its a simple function that needs to be done. also the original task didn't involve any "Acustic or LED signalisation".

just a point, dont always jump straight to PICs
Well, I still think PIC is better comparing to OPamp + relay, remember PIC is just 8pin device... But I agree that it's not suitable for beginners.
 
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