pure_insanity Posted March 16, 2014 Report Share Posted March 16, 2014 i know i can use a 555 timer to turn on and off gadgets but im no electrical engineer and everything i have found seems to e pointed at someone smarter than me. Can someone give me a simplified diagram of a 555 timer that shows it in laments terms? Like 12v pos. Goes here and this terminal is the output and this one does that. Etc. Thanks in advance. Link to comment Share on other sites More sharing options...
kidjc Posted March 16, 2014 Report Share Posted March 16, 2014 I'm sure there are others, but try Scott87star. Link to comment Share on other sites More sharing options...
ucw458 Posted March 16, 2014 Report Share Posted March 16, 2014 Try youtube Link to comment Share on other sites More sharing options...
kidjc Posted March 16, 2014 Report Share Posted March 16, 2014 Well... I watched it... still just as close, or far away from it as I was/ Glad y'all understand all this! Yippee I Oh Kai Aehhhh! Link to comment Share on other sites More sharing options...
scott87star Posted March 17, 2014 Report Share Posted March 17, 2014 Yeah, I think it makes the point that you don't just stick wires on the end of the chip, you have to decide what you want to do and build an appropriate circuit for it. Link to comment Share on other sites More sharing options...
87redcat Posted March 17, 2014 Report Share Posted March 17, 2014 Its a good basic chip. there should be some diagrams of circuits on the web. My notes are all back home stored away and I'm in Pittsburgh for a few days. Its a timmer chip so clocks are its primary if I remember correctly. But everything can have dual purposes Link to comment Share on other sites More sharing options...
apate Posted March 17, 2014 Report Share Posted March 17, 2014 Here is the data sheet for the 555 timerLook at page 9-15 for sample circuit and application http://www.ti.com/lit/ds/slfs022h/slfs022h.pdf It can only drive 200 mA (.2 amps) What are you trying to do? Link to comment Share on other sites More sharing options...
pure_insanity Posted March 18, 2014 Author Report Share Posted March 18, 2014 I want to use it to control some pneumatic valves that i want to use for my idle air control. I was expecting to need a relay to control the valve itself. I just need the timer to supply the switch. Link to comment Share on other sites More sharing options...
ucw458 Posted March 19, 2014 Report Share Posted March 19, 2014 (edited) I may have a better solution for you. Late 80s early 90s volvos used a divorced idle valve connected by hoses. The 2 wire version is perfect for a PWM output from any standalone. You can find them in junk yards for cheap. Also when they are off or fail they are in the open position so if one fails your car will still idle. http://i00.i.aliimg.com/photo/v0/376621576/Idle_Speed_Control_Valve_for_Volvo_460L.jpg Edited March 19, 2014 by ucw458 Link to comment Share on other sites More sharing options...
apate Posted March 19, 2014 Report Share Posted March 19, 2014 Check out the site: http://555-timer.clarkson-uk.com/operation/frames3.html It has a good circuit drawing and form for calculating the proper resistor and capacitor for the desired time delay. Link to comment Share on other sites More sharing options...
pure_insanity Posted March 19, 2014 Author Report Share Posted March 19, 2014 I may have a better solution for you. Late 80s early 90s volvos used a divorced idle valve connected by hoses. The 2 wire version is perfect for a PWM output from any standalone. You can find them in junk yards for cheap. Also when they are off or fail they are in the open position so if one fails your car will still idle. http://i00.i.aliimg.com/photo/v0/376621576/Idle_Speed_Control_Valve_for_Volvo_460L.jpg Link to comment Share on other sites More sharing options...
pure_insanity Posted March 19, 2014 Author Report Share Posted March 19, 2014 I picked one of these up at a junkyard a while back but i never really gave it a whole lot of thought after i figured out it was normally open in the off position. How would you plumb it in? I thought you would have a boost leak when it wasnt operating. Or would you tell the standalone to go from open to closed and hold it closed? Seems like it would need to be normally closed and it only opens up asneeded then cuts off in a closed position. Link to comment Share on other sites More sharing options...
psu_Crash Posted March 19, 2014 Report Share Posted March 19, 2014 (edited) I have run a valve similar to that using PWM. Mine was closed when it was "off" although when there was no PWM signal present providing a ground signal I ran the other un-used wire from the 3 wire valve through a power resistor to ground in order to help it operate faster and keep it closed.Like so http://www.77e21.info/photogallery/megasquirt/Bosch-valve.JPG Edited March 19, 2014 by psu_Crash Link to comment Share on other sites More sharing options...
ucw458 Posted March 19, 2014 Report Share Posted March 19, 2014 I picked one of these up at a junkyard a while back but i never really gave it a whole lot of thought after i figured out it was normally open in the off position. How would you plumb it in? I thought you would have a boost leak when it wasnt operating. Or would you tell the standalone to go from open to closed and hold it closed? Seems like it would need to be normally closed and it only opens up asneeded then cuts off in a closed position. Inside is a wheel that turns like a valve as the PWM frequency increases. In it's off position it exposes an opening to allow some air through. To close it you apply a PWM signal of I'm guessing around 10%. Then when you need idle air you increase the PWM signal and the wheel turns farther to expose the running portion which is a larger opening. The off bypass port is small. Just enough to let it idle but not enough to idle well. I have one of these but I never set it up properly in my ECU. You log into your ecu and play with the idle PWM frequency until you see the valve just about to open. Then you set that as your base frequency. The ECU will know to start there and increase for more idle air. What I did was tap a hose fitting before the TB and connect the idle valve to it. Then I connected the idle valve to the back of my magna manifold. There is another idle valve style from volvo. This one is thinner and it's just a plunger. So when it's off it's closed. It looks like this. But they are much harder to find in junkyards. http://www.swedishautoparts.com/catimages/Volvo-Idle-Control-Valve-1389557-OES.jpg?mt=1349112801 Link to comment Share on other sites More sharing options...
Recommended Posts