Rudy the problem with your circuit cutting out at higher voltages is that you are grounding out the signal output with the points. I have and use the A1120EUA so I have some experience with it. The A1120 has a built-in voltage regulator and short circuit protection control, the 2 are seperate. The circuitry can provide up to 25ma of current continuously and will trip at 30ma according to the data-sheets. The signal out was never designed to be grounded out, this would put it into a short circuit condition. Like most over current protection it is a latching design and will not reset until the power has been removed and turned back on but, if the condition remains it will lockout again. I don't know the reason for using both a Hall-Effect and points, it should be one or the other.
If your going to use the circuit the way you have it then add a resistor between the points and the Hall-Effect signal as a pull-down resistor that limits the current also then use this formulae V/I=R or properly E/I=R which is 12/0.025 = 480 ohms, 6/0.025 = 240 ohms and so on. I haven't looked at the rest of the circuit I'll do that later and get back to you.
I found if your going to use 555 timers and make a buzz coil and have it work properly you need 3 x 555 circuits. 1 to work as a variable oscillator and the other two to work as what is know as a one-shot mulivibrator. The one-shot circuit can be set up as a non-retriggerable so it gives one pulse out for one pulse in and will not except another in until the first is done, good for debouncing points at high RPM. It will not stay on because you can set the pulse wide to the coil circuit.
I'm making a line of small ignition systems soon and at a price point that I think everyone will like in kit or assembled. The buzz coil is the next design I'm working on. I need to make money so I can buy equipment.
Gnite
Ray
If your going to use the circuit the way you have it then add a resistor between the points and the Hall-Effect signal as a pull-down resistor that limits the current also then use this formulae V/I=R or properly E/I=R which is 12/0.025 = 480 ohms, 6/0.025 = 240 ohms and so on. I haven't looked at the rest of the circuit I'll do that later and get back to you.
I found if your going to use 555 timers and make a buzz coil and have it work properly you need 3 x 555 circuits. 1 to work as a variable oscillator and the other two to work as what is know as a one-shot mulivibrator. The one-shot circuit can be set up as a non-retriggerable so it gives one pulse out for one pulse in and will not except another in until the first is done, good for debouncing points at high RPM. It will not stay on because you can set the pulse wide to the coil circuit.
I'm making a line of small ignition systems soon and at a price point that I think everyone will like in kit or assembled. The buzz coil is the next design I'm working on. I need to make money so I can buy equipment.
Gnite
Ray
