streets97f

audioguru: Are you suggesting adding a voltage regulating circuit like this one: http://ourworld.compuserve.com/homepages/Bill_Bowden/page12.htm Yes there is a 1M res. in series but i think i have a 20% ver. pot when i should of bought a 15% var. res. with a lot of turns. I really know very little about electronics (i'm a bio major) so, if you guys could explain the descusion over the zener diode it would help. also, Alun I couldn't find a simple pulse gen circuit with a NE555...maybe you could point me to a site. thanks all... you all are very responsive, unlike other forums

Well i noticed as i i adjust the variable resistor past a certain threshold the circuit just puts out a continual voltage (6.8v and up) and the 2n2222 and the 50 ohm resistor get hot, but when backed down, the pulsing resumes and all is fine. Yes the ECU wants 5v. My understanding is that the var. resistor is there to adjust the voltage. If i choose a 12v source, can i adjust it to 5v?

I building a pulse generator in an attempt to mimic the speed sensor on my car. (The speed sensor just generate pulses based on the rate of the turning transmission axle.) Here is the circuit i'm using: http://www.electronics.50g.com/cpg.htm I hooked up a 9v batt. to it and it feels like the 2n2222 is getting hot. I'm worried that the car ECU might draw too much current for the transistors. Can anyone suggest higher current substitutes for the 2n2222 and 2n2907A trans. I'm really a novice and would appreciate and suggestions.