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| Electronic Projects Design/Ideas/Reviews Are you building an electronic project or want to? Maybe you need some assistance? Come and submit your electronic questions here and let our experienced members find a solution. |
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Thread Tools | Display Modes |
22nd March 2004, 08:37 PM
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alarm with resistor
is it possible 2 have an alarm, were the alarm is switched on/off wen a certian value resistor is inserted (e.g, the resistor is in a key, so wen the key is inserted the 2 contacts make contact with the alarm, the alarm measures the resistance nd if itz within a certian resistance, the alarm is switched on/off)
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22nd March 2004, 10:47 PM
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Easy to do. Do you have another question?
__________________
see my website: www.geocities.com/russlk |
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23rd March 2004, 02:15 PM
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Quote:
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23rd March 2004, 02:48 PM
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Thats basically what my car has. I don't know how it works but the key has a tiny resistor on it, and when the resistor is inserted it allows the car to start but if the resistor is not there it would not allow the car to pump gas.
So if someone tried to steal the car and pick the lock or break the lock the car wouldn't start without that specific resistor. My guess is they use somekind of PIC. |
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23rd March 2004, 05:08 PM
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Just use a window-comparator and delay (to prevent with potmeter opening)
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Linear Mode
