pi coil connections

[homefire]

In fact the coil could be connected between Ground and Neg .

It could be connected between -12 and +12 .

It could be connected Positive or Negative Ground.

It just depends on how the circuit is set up.

What is best is what works with the parts you have to do the job.

Some PI circuits use a Spit power supply with a false ground.

[taliesin]

In fact the coil could be connected between Ground and Neg .

It could be connected between -12 and +12 .

It could be connected Positive or Negative Ground.

It just depends on how the circuit is set up.

What is best is what works with the parts you have to do the job.

Some PI circuits use a Spit power supply with a false ground.

you've changed your tune a bit there.perhaps someone else could come in and give some valuable input to this discussion.either way one method should make for some more ideas

[homefire]

I've not changed a thing.

I've just stated facts.

Neg, Pos it makes No Difference as to performance.

[taliesin]

I've not changed a thing.

I've just stated facts.

Neg, Pos it makes No Difference as to performance.

it does make a difference !!! to the capacitance added from the shield ,if you use one.if you use no shield no problem.if you use shield it makes a difference .try it yourself and see.i admit i cannot express it in mathematical terms as many on this forum can.but try it.i just want some comfirmation to expalin this.

[Carl-NC]

Taliesin,

Connecting the coil to +V or -V doesn't make any difference with shielding or capacitance. The only difference is in how you drive the coil; either with a P-type device or N-type device. Generally, N devices (NMOS & NPN) make better switches, so I tend to connect coils to +V and drive them with an NMOS device. Then, I simply call +V my "ground" and reference everything else to that. The circuit doesn't know any better.

- Carl

[taliesin]

Whaa? Suggesting that HH1 coil is not connected to ground? You're being absurd. HH1 coil IS connected to ground. Your arguments are senseless.

oops .didn't see that ground sign last night apologies

[taliesin]

Taliesin,

Connecting the coil to +V or -V doesn't make any difference with shielding or capacitance. The only difference is in how you drive the coil; either with a P-type device or N-type device. Generally, N devices (NMOS & NPN) make better switches, so I tend to connect coils to +V and drive them with an NMOS device. Then, I simply call +V my "ground" and reference everything else to that. The circuit doesn't know any better.

- Carl

nice polite answer carl.i'm gonna mess around with this anyhow .