jtjohnston

Created a simple car alarm once. http://jtjohnston.net/relay.PNG Put a jumper from pin 1 to the normally open pin (pin 5). Pin 3 has continuous juice. Juice pin 1 once and the relay will lock on until the ground or juice on pin 3 is broken. Sounds like it might help?

I suppose you've seen these? http://store.qkits.com/category.cfm/CAR They seem to have a decent digital tachometer. Any one know where a newb might find an oil pressure gauge, water temperature, voltage, battery charge? I have an old Chevelle, and although it is Gino a bit I wouldn't mind having a kit box with a few diagnostics. Serious question. Where might I find a kit? John

Any idea on how to calculate C1, R1 & R2?

I'm a 41-year old newbie. Haven't played with this stuff since I was 20. I still know a few principles. So be gentle. Here goes. I want to create an RC circuit to create yee old alternating, blinking relay. Instead of powering the relay through the coil, (pin 1) I'm juicing it through pin 4 by placing a jumper between pin 1 and pin 4. Therefore, when 12 v dc passes through pin 4, it will activate the coil, pin 1, and fire to the normally open position. When it looses juice it pops back to the normally closed position. The question is how to keep the relay alternating every 1 second. If I use a RC circuit between pins 1 and 4, using an RC circuit charge and decay, I should be able to make the relay alternate. That is as far as what I remember what to do. I have a regular automobile SPST relay, the coil measures about 900 ohms. What values do I need for R1, R2 & C1. My idea of using R2 was to help C1 decay faster. Eventually I would put a pot for R2 to control the decay rate of the RC circuit. Can anyone help? Am I looking at this the right way? I do plan to experiment with a 555 circuit later, but want to try and do this old-school first. John