The valve will not drop out between pulses.
And I don't want it to. When it's done with that cycle, I'll simply
turn it off.
The idea is to snap it on hard with a longer pulse and then
shorten the duty cycle to ease back on the current.
I came up with the driver amp that will return the energy to the
power supply. I now simply need to create a pulse timer that has a
long pulse width on first initial start and then start pulsing with
a shorter duty cycles. When that request is done from the external
trigger source, it will simply turn off the clock source I have for the
It's as simple as that.
We will most likely be using a throttle body type TBI and they require
a lot of current on the initial pull and then it needs to be eased back
to not burn out the coil. This is where the PWM duty variation comes
I will need to also have a one-shot timer to adjust the over all
demand on each cycle.
I suppose one could do this with a dual 555 timer. One as the
One-shot the other has the PWM signal.
There is a way to set up a 555 timer to have a longer starting pulse,
that maybe the easiest thing to do for this.
I was also thinking about using a LM324 type chip and current sense
to create a hysteristic pulse where I can simply vary the current as the
portion control on the holding current.