seperately excited dc motor control

[engineer1000]

I have a littlefuse applicatin note AN1003.16 FOR TRIAC speed control for permanent dc motor. I want to control a seperately excited dc motor. 100v dc field and 90v dc armiture.
Can I use this to power the armiture and used a rectifed circuit to permanently power the field winding.?

 

[srizbf]

I have a littlefuse applicatin note AN1003.16 .......
Can I use this to power the armiture and used a rectifed circuit to permanently power the field winding.?

if you intend to use fig 16 of the application note ,
for connecting armature then it is feasible.

only constraint may be you have to take care that the phase control variable pot should not exceed the 90volt across the armature.

 

[engineer1000]

if you intend to use fig 16 of the application note ,
for connecting armature then it is feasible.

only constraint may be you have to take care that the phase control variable pot should not exceed the 90volt across the armature.

That's exactly what I want to do . I was a little worried that at start up I would still get too much current through the triac due to the low armiture resistance

 

[engineer1000]

That's exactly what I want to do . I was a little worried that at start up I would still get too much current through the triac due to the low armiture resistance

Now only have one problem. The motor changes direction using two switches conected to the field winding operated by a lever. The problem is it has a neutral position where the field winding is not connected. At this point i have the armiture powered. I need to find a way to only allow current through the armiture when the field winding is connected. Any ideas ?

 

[engineer1000]

seperately excited dc motor control problem help

I am trying to run a seperately excited dc motor. my field winding is powered via a110vac full bridge straight on to the windings, which is fine. the armiture is powered using a full bridge and a triac on the ac side, to reduce the dc voltage , with the trigger connected to MTS VIA resistors and pot ( little fuse AN1003.16). My armiture resistance is 3.4R. The first thing I did was put a 2k2 resistor inplace of the armiture winding , When I moved the pot the voltage changed from approx 10v to 50v dc on the dc side.
When I connected it up to the armiture the triac stopped conducting. does anyone know why? the triac is a 40A device .
I have had the motor turning with the field winding powered and a power supply across the armiture winding with a voltage of 10v dc
help

 

[srizbf]

Re: seperately excited dc motor control problem help

I am trying to run a seperately excited dc motor. my field winding is powered via a110vac full bridge straight on to the windings, which is fine. the armiture is powered using a full bridge and a triac on the ac side, to reduce the dc voltage , with the trigger connected to MTS VIA resistors and pot ( little fuse AN1003.16). My armiture resistance is 3.4R. The first thing I did was put a 2k2 resistor inplace of the armiture winding , When I moved the pot the voltage changed from approx 10v to 50v dc on the dc side.
When I connected it up to the armiture the triac stopped conducting. does anyone know why? the triac is a 40A device .
I have had the motor turning with the field winding powered and a power supply across the armiture winding with a voltage of 10v dc
help

if you can attach the actual circuit you have wired for the control , then it may be helpful to find the cause .