Protection circuit ULN2803

jorginho1877 said:

Hello Everyone

In this post I want to ask if you know of any circuit that can protect the integrated ULN2803, because when I make the connection to a stepper motor it overheats and stops working correctly, or I advise to use another reference to control the motor Step by Step?

ULN2803

I am using a voltage of 9v on the COM pin with a current of 0.6 A

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audioguru said:

The ULN2803A has a maximum allowed current from one output of 500mA so you are overloading and cooking yours with 600mA.
Is more than one output turned on at the same time?
What feeds the inputs and at what voltage?

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jorginho1877 said:

Hello

the eight outputs are turned on, because I'm controller 2 stepper motors, the ULN input is 5v

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gophert said:

The negative wire (ground) should be on the common pin.

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KeepItSimpleStupid said:

Nope! Common is common of all of the free-wheeling diodes. You have in and ground used so you get inputs to the base of the transistors. Out goes to one end of the solenoid and that has the cathode of the diode connected.

Now where would the anode of that built-in diode go?

The other end of the relay/solenoid which happens to be the +supply to the relay/solenoid and they can go to a COMMON point, the +supply of the solenoids/relays.

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