feynman137:
Thanks brother. Found this H11L1M on amazon with a short lead time.
If you're okay with spending that amount of money and getting 100 of them.
You can get a H11L1-MQT-ND from Digikey for $1.25 (I see CAD so cheaper in USD), as few as qty 1 -- ten of them will cost $8 -- with FedEx overnight shipping for $8 (again, CAD, so likely cheaper in the US)...
I see, when I first looked at Digikey I saw a lead time and thought no way.
But now I see that it can be shipped immediately, so better option for sure.
I never buy ICs from questionable Amazon and ebay sources.
In the US, I use Digikey, Mouser, Arrow, Avnet as my sources.
Reputable distributors, all ship the same day I think if ordered by 7PM eastern or something like that.
PEConnectors.com has a great selection of headers nicely organized, makes it easy to find stuff. Digikey & Mouser have so many it can be difficult to find things.
Pololu.com is a great source for Female PCB headers, crimp terminated wires, and crimp housing.
Long tail female headers are a little trickier. We've had good luck with Gikfun on Amazon, buying hundreds to thousands of 8, 10, and 36 pin headers at a time; we're not your usual hobby purchaser!
H11L1M, >10,000 in stock at Digikey
https://www.digikey.com/en/products/detail/on-semiconductor/H11L1M/284866
| QTY UNIT PRICE EXT PRICE |
|---|
| 1 |
| 10 |
| 100 |
Plus shipping/mailing & sales tax.
Did you mean H11L1SM in your earlier post, #15? (vs H11L1MS?)
https://www.digikey.com/en/products/detail/isocom-components-2004-ltd/h11l1sm/5036962
CrossRoads:
Did you mean H11L1SM in your earlier post, #15? (vs H11L1MS?)https://www.digikey.com/en/products/detail/isocom-components-2004-ltd/h11l1sm/5036962
I don't think so, I was referring to the opto recommended in post #4.
Don't worry. I say, almost every opto would do in this application. You don't need optos handling MHz.
feynman137:
I see, when I first looked at Digikey I saw a lead time and thought no way.But now I see that it can be shipped immediately, so better option for sure.
Yeah, they have 10,500 in stock. You should be okay 
Blackfin:
Yeah, they have 10,500 in stock. You should be okay
That'll do.
I am going to make one of these as well. I will follow the circuit shared and use a Metro M4 AirLift as I may add some wireless functions based on the RPM. I will also use an Adafruit 2.4 TFT shield for my display.
I chose this hardware because I am already writing code for the M4 to act primarily as a speedometer, secondarily as a tachometer, and tertiary as a O2 sensor's display.
Thanks for telling us.
I got the circuitry in and set the it up as describe by blackfin. Before I connect to the tach line though I was hoping to use a signal generator and oscilloscope to simulate the process and make sure things are working The max voltage I can generate is +/- 10V, but this should be fine.
The problem is the circuit appears to only have one connection to the ignition coil, so how will it work. Also the connection is to the negative instead of the positive terminal, which I thought was odd. So will I be okay to simulate the process if I connect the signal generator's positive where the ignition coil negative is shown in the diagram and the generator's negative to the ground?
Using the negative and picking up the ignition pulse was the construction I used used. Can You post a wiring of that part? Just to be sure.
feynman137:
I got the circuitry in and set the it up as describe by blackfin. Before I connect to the tach line though I was hoping to use a signal generator and oscilloscope to simulate the process and make sure things are working The max voltage I can generate is +/- 10V, but this should be fine.The problem is the circuit appears to only have one connection to the ignition coil, so how will it work. Also the connection is to the negative instead of the positive terminal, which I thought was odd.
Connect your circuit ground to the chassis/battery negative of the vehicle.
The points in the distributor switch the low (-ve) side of the coil; that's the side you want to monitor.
Railroader:
Using the negative and picking up the ignition pulse was the construction I used used. Can You post a wiring of that part? Just to be sure.
The attachment shows how the coil would be connected, but I was having trouble finding wiring for the actual ignition coil part. It looks like what you guys are describing is the correct method, that is to connect to the ignition coil negative and battery negative. And in the diagram and blackfin's description I can see more clearly that there are two connections.
But if I am trying to recreate this ignition coil's pulses with a signal generator, how would I connect the positive and negative leads of the generator to the circuit?
Right now I am trying to do so by connecting the positive lead of the generator to where the ignition coils negative would normally connect to the circuit, and the ground of the generator is connected to circuit ground. I am getting pulses measured by the optocoupler with this route but it doesn't seem correct because they are much less than the logic side supply voltage.
Sorry, I turned things up side down and was totally wrong. Use spikes at the positive side of the ignition coil, some simple limiting circuitry and an opto coupler.
New approach, nice, but not so easy to read as a pen and paper drawing. What is it You want to show?
I don't understand the generator part. What do You want to tell by that? Where is the ignition coil?
Railroader:
New approach, nice, but not so easy to read as a pen and paper drawing. What is it You want to show?
I don't understand the generator part. What do You want to tell by that? Where is the ignition coil?
I agree, not as easy to follow, but the point of this is that I can make the generator create almost any frequency I want. Instead of hooking to the ignition coil and revving the engine. In this example I have the generator set to make square waves and I am adjusting the frequency from 0-200Hz.
Do You say that You some how pick up the engine RPM by monitoring the generator? It sounds like doable but using an oscilloscope between ground and ignition coil + You ought to find a useful signal.
Railroader:
Do You say that You some how pick up the engine RPM by monitoring the generator? It sounds like doable but using an oscilloscope between ground and ignition coil + You ought to find a useful signal.
There is no engine/ignition coil in my garage, but I am simulating its pulse signals with the generator so I don't have to drive to engine location.
I already know that the ignition coil generates a signal 0-200Hz so I don't need the o-scope for this. The point of the generator is that it generates the same frequency and squarewave signal that the ignition coil will. Therefore if the circuitry works with my signal generator it will work on the ignition coil signal on the actual engine. I am monitoring the signal out of the optocoupler with the o-scope to see if the circuit is working.
