I need a timer relay for a project that I am working on. The relay has to be cheap as possible. I need a timer relay i can hook a 9 volt battery up to and set the timer on the relay and when the time is up 7-9 volts of current is released to the out put. I prefer the relay to be minutes or hour intervals. i think i get the jist of how relays work but which one will hook up to a 9v battery and release 7-9 volts when the timer goes off? is this possible or am i way off base? Any help or suggestions would be appreciated. Someone point me in the right dirrection.

will this work
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&Item=350167531023&Category=4661

Or how bout this
http://cgi.ebay.com/DEI-528T-12-VOL...286.c0.m14&_trkparms=66:2|65:15|39:1|240:1318

please help

 

Ebay choices do not look promising, not enough inf. Try a one minute period oscillator, 8 bit counter, couple of 8 input AND getes low current SCR , relay and plug board.

 

could u be more specific?

 

If you had a schematic for a timer, could you build it?
Need more information on timing requirement, one to ten minutes in one minute incriments ? ;or continuously variable ? How long ?
Can you decode an 8 bit binary counter?

 

well i sappose i could build it from schematics, i can soilder or i could get a plug board. Isnt there just a timed relay I could buy that i could hook a 9v up to and when the time is up 9vs or a little less is discharged. cheap and easy. 8 bit binary? no afraid not...I want second intervals up to an hour or more....no less then thirty seconds.

 

is there a kit i could buy with a plug board and all the things i would need to make the timer

 

I do not know of such a timer or kit; cheap, about $ 5 US max in parts. Second intervals in 2 hrs. = 7200, big order. After you finish ckt. you will be an expert at programming time on a pair of DIP Switches, esp if interval can be stretched to 10-60 sec.

 

When it comes to long timing lm555 is particularly suited for it.Time from microsec to-hours is possible. And since he can drive 200ma means a relay can interface directly or supply 200 ma to your circuit as a switch but only for 200ma.

 

If using a 555 for long (hours) periods, a low-leakage capacitor is required.