I want to design 10 A constant current power source to pass constant current through a helmholtz coil. I don't have much experience in power electronics.
Any kind of help will be appreciated.
Thanks.
Any kind of help will be appreciated.
Thanks.
Designing 10A constant current power source (0-50 V)
- Thread starter johnpete001
- Start date
I have to build it from scratch.
@crutschow "work work for that" ???
What experience do you have regarding reading schematics and building circuits ?
Do you know how to solder properly?
I want someone to help me design it. I don't even know if what I am asking is actually a easy thing to design or not. But I have to design it to complete the project I am carrying out right now
Start by choosing a transformer that can give out 10amps or more any low voltage from 30V will do, then use an op amp and power transistor to set the current in the coil, plenty circuits on google.
30V won't do.
Transformer secondary figures are for a 0-50VDC , 0-10A output:
To use a full bridge capacitive filter OP would need 42V @ 15Amps ( with headroom ) secondary rating.
To use a CT full wave capacitive filter OP would need 85V @ 11Amps ( with headroom ) secondary rating.
He need to choose the Tx depending on it's usage. For full continues operation, OP might need to beef up the secondary more than suggested for cooler operation.
Is this a project for school? If so, what are you expected to do as part of the assignment? Since you have to build it from scratch, it seems likely the idea is for you to design it as well. So sketch out the design as best you can and ask for thoughts and suggestions on it and then use those to improve your design.
What is the inductance of this coil?
What is the DC resistance?
What is the tolerance needed on the current?
How fast does it have to charge?
DickCappels
- Joined Aug 21, 2008
- 10,180
And do you have a specification for noise and drift (such as PARD -Periodic And Random Deviation)?
DickCappels
- Joined Aug 21, 2008
- 10,180
Go get some larger wire. 10A x 263V = 2,630V. Not sure you could even buy a suitable power supply. Best to use larger gauge wire and try to get the resistance down to a few ohms.
Oh no I m sorry. A typing mistake. Its 2.63 ohm.
Tolerance needed on current is 0.1%.
That would be a lab quality instrument. Given the high power and high accuracy needed, not something an amateur (even one like me, who has been doing it for 60 years) is likely to succeed at.
Also, since you need 0.1% accuracy, you cannot have much ripple at all, which probably means a linear circuit, which means massive heat sinking capability. I would estimate this thing will weigh about 50 lbs and need lots of airflow for cooling.
Bob
If you don't have much experience; PWM constant current is probably out of reach.
A 10A linear regulator handling up to 50v is going to be a lot of power transistors and a rather big heat sink.
You will probably end up using forced air cooling (fan).
