• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

power transformer

Status
Not open for further replies.

Mdkanz

New Member
I have a 7.2v dc 2100 ma power supply that i am using on a dc motor. i was wondering if all power supplies get hot or is it my motor. (it gets almost to hot to touch)
 

crutschow

Well-Known Member
Most Helpful Member
Too little info. Can't tell you that until you tell us the voltage and current rating of the motor.
 

Hero999

Banned
Put a multimeter set to 10A in series with the motor, if >2.1A is indicated on the display then the supply is being overloaded and might be damaged if it's left running for too long.

Make sure the load you intend to drive is connected when you perform this test or the results won't be valid.
 

audioguru

Well-Known Member
Most Helpful Member
Transformers that are made in some countries are absolute garbage.
I have a Chinese one that is almost red hot with its rated load. Maybe it has an internal short (except it is not too hot without a load) and maybe the manufacturer "forgot" to install a thermal fuse.
 

leitmotif

New Member
Overload ??

I have a 7.2v dc 2100 ma power supply that i am using on a dc motor. i was wondering if all power supplies get hot or is it my motor. (it gets almost to hot to touch)
I would bet you are trying to drive a motor that is too large for the power supply ie more than 2.1A on 7.2 VDC line.
Power supplies will get warm 100 and maybe hot 120 or so if too hot to touch something is wrong.

Dan Bentler
 

tcmtech

Banned
Most Helpful Member
Perception of hot is relative to the person. I work with some commercial and industrial stuff thats not considered over worked hot until near 200 F or above on the heat sinks.

120 F is no big deal for typical electronics. Most stuff has ambient air temp ratings around that.

Too hot to touch is around 140 - 150 F. If its a cheap motor or transformer 150 F may be near its design limit though.

If its starting to smell like the insulating varnish is cooking then yes its to hot for its design.
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top