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**BrewBeemer** · 10-27-2009, 06:36 PM

I've gone back 25 pages on both the DIY and Equipment section and have not located this posting or a reply by another member.
Had it in my bier files that have been cleared out and not by me, pisser.
Anyone have that posting or reply so I can wire up a 555 timer? Thanks
in advance.

**jkarp** · 10-27-2009, 06:53 PM

Here's one link to a 555 based PWM controller.

nicknunns · 10-27-2009, 06:54 PM

Was it used as a single-shot or with a varying duty cycle to control? 555s are pretty simple and most configurations are similar, just with different R/C values to change timing of pulses.
Can you give more info on the application?

nicknunns · 10-27-2009, 06:56 PM

Also might I recommend looking into an Arduino to control this? I've been working on a temperature controller using one. I'm a complete idiot when it comes to programming and I've still managed to piece together code that will probably work (haven't fully tested yet).

**pickles** · 10-27-2009, 06:59 PM

Mike's E-Kettle

Is this it?

**BrewBeemer** · 10-27-2009, 07:13 PM

Quote:

Originally Posted by nicknunns

Was it used as a single-shot or with a varying duty cycle to control? 555s are pretty simple and most configurations are similar, just with different R/C values to change timing of pulses.
Can you give more info on the application?

I would want it to be a variable duty cycle from low as I can go to at least 80%, from there I can jumper the power supply directly to the unit I have in mind.
Please don't shoot me this is not a bier related project but as a variable pulsing unit used to flush forwards, backwards as well check the flow volumes and spray patterns for fuel injectors. I'm in the middle of a project changing from single spray nozzle to 4 hole injectors wanting not to only clean but make up a matched set of 8 that have a balanced flow volume of injectors. A smog test is needed next month. Question I have what is the minimum time in Ms a SSR can be switched at? I bet the 555 with go higher with the proper R/C added. I'm needing 1.5 to 2 Ms minimum in time to 80%, I can switch or jumper to 100% if not I must due with what's available. The flow volumes at the lower pulse width are what i'm after in balance as well the flows to 80% on pulse time and volume balance.
Thanks for the fast replies.

leboeuf · 10-27-2009, 07:41 PM

How many amps do you need through the SSR?

The smaller the current you'll be switching the more high speed options you will have....

**kladue** · 10-27-2009, 07:49 PM

[Not sure what happened to the old post but here is a link to a page with the info you need for a PWM output 555 timer circuit. http://www.dprg.org/tutorials/2005-11a/index.html"]

**BrewBeemer** · 10-27-2009, 08:04 PM

Quote:

Originally Posted by leboeuf

How many amps do you need through the SSR?

The smaller the current you'll be switching the more high speed options you will have....

I believe in the 1 amp range, i've heard of 4 to 6 amp but again special 42# /hr racing injectors. I'm in the stock zone so 1-2 amps my maximum switching load at 24# an hour injectors.
To have 100% at 43.3 psi regulated pressure with a carb cleaner like Berrymans B-12 is great for cleaning in both directions but the flow measurements at reduced duty cycle are real life driving conditions. This is where the minimum flows from at idle to normal driving of balanced injectors play the biggest part in smooth running as well smog testing. This in a 95 landRover Discovery full time 4 x 4 hence no dyno just the sniff test so low duty cycles without a engine load. Balanced sets of injectors play a big part also, one flowing higher and richer then the O2 sensors will overly lean down that bank of cylinders with the other 3 injectors leaned down. I was thinking of the treadmill motor of 1 1/2 HP 90 VDC I have from 240 rpm's to 4,250 rpm's driving a old 8 cylinder distributor with a 0.005" point gap as a vary narrow and low duty cycle and vary the rpm's as a trigger to the injectors. I have a Burette tube to 100cc with 8 pin electronic brick timers for balance checking. You now see what i'm looking for in this testing project?

MacBruver · 10-27-2009, 08:05 PM

The homebrewtalk google search works way better for searches like this:

http://www.homebrewtalk.com/gtsearch.php?cx=016873362520281466893:xvnx8yvgpla& cof=FORID:11&q=555+pwm

I think the first result is what you're lookin for.