RC Network to act as a battery for time delay
RC Network to act as a battery for time delay
(OP)
Please help:
I have a 4160 V starter. I want to delay the starter from shutting down the motor by a 20 cycle delay.
I am trying to achieve this using an RC Network. (Basically I want the capacitor to act as a battery for 20/60 = .333 sec. longer)
The circuit is: starter coil connected in parallel w/ the motor contact. I will place my RC circuit in parallel w/ the contact.
I have the values of coil resistance = 541 ohms
My RC capacitor value is= 235 /microF/
How can I find the value of the RC Network "R" resistance needed to accomplish my task?
Are there any other things I need to consider?
I have a 4160 V starter. I want to delay the starter from shutting down the motor by a 20 cycle delay.
I am trying to achieve this using an RC Network. (Basically I want the capacitor to act as a battery for 20/60 = .333 sec. longer)
The circuit is: starter coil connected in parallel w/ the motor contact. I will place my RC circuit in parallel w/ the contact.
I have the values of coil resistance = 541 ohms
My RC capacitor value is= 235 /microF/
How can I find the value of the RC Network "R" resistance needed to accomplish my task?
Are there any other things I need to consider?





RE: RC Network to act as a battery for time delay
Mike Halloran
Pembroke Pines, FL, USA
RE: RC Network to act as a battery for time delay
RE: RC Network to act as a battery for time delay
The RC only works as a DC "battery". And your coil is AC. I think that you shall drop that idea and use some other technology.
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: RC Network to act as a battery for time delay
JRaef.com
"Engineers like to solve problems. If there are no problems handily available, they will create their own problems." Scott Adams
For the best use of Eng-Tips, please click here -> FAQ731-376
RE: RC Network to act as a battery for time delay
There is an undervoltage relay connected to the motor, when it sees a 20% voltage dip, it will open, killing the control ckt, where the starter is located, and motor starter coil (where I want to put the RC Network).
By it opening, it will not supply any more ac to the control ckt therefore de-energizing the motor start coil.
So here is my scheme: By no more AC power, this will now look as a DC ckt: The coil will behave as a 541 ohm resistance, and I want to parallel connect my RC Network to act as a battery, so the control will never see the relay open, nor the dip and therefore I do not have to go and start the motor over and over again.
I have the value of the motor coil resistance, and I have the RC cap value, but how do I go about and get the R value?
RE: RC Network to act as a battery for time delay
RE: RC Network to act as a battery for time delay
One manufacturer I worked with had to use a 20A analog supply (lots of big caps)to supply the coil of a main contactor to keep it from dropping out on a foreign voltage supply that would suffer from 1/4 second drop outs.