Easy way to get a 500mA load for testing?

[Jay112]

I'm sorry for this simple question, and I feel like the answer should be obvious to me, but...

I'm trying to test some triacs using this simple SCR tester circuit that I got from this page: http://www.sentex.ca/~mec1995/tutorial/triacs/triacs.html


The triacs I'm trying to test have a 500mA latching current, but I'm having trouble thinking up a way to get a 500mA load. I can get the triacs to switch on using the circuit above, but I can't test their latching ability because I need a greater load. Can you please give me some suggestions for how I can make/find a 500mA or greater load?

Thanks!

[Delta]

A lamp, just like your picture shows!

6W at 12V is 500mA, so try a car sidelight or indicator bulb...

[klr5205]

A simple current mirror can be made with 3 parts: a transistor, a resistor, and a diode (or diode-connected transistor)

The other obvious answer is of course just a 24 ohm resistor.

[Jay112]

A lamp, just like your picture shows!

6W at 12V is 500mA, so try a car sidelight or indicator bulb...

Thanks for responding! I couldn't seem to find any lamps that are higher than 500mA. The best I could find was a 1W 12V LED.

A simple current mirror can be made with 3 parts: a transistor, a resistor, and a diode (or diode-connected transistor)

The other obvious answer is of course just a 24 ohm resistor.

Thanks for the info! I'll have to study about current mirrors now, and I'm sure that'll be useful to me in the future. But I think the obvious answer of just using a resistor was what I was looking for. My mind wasn't working well because I'm tired of concentrating on circuits since yesterday.

[karoru]

A simple current mirror can be made with 3 parts: a transistor, a resistor, and a diode (or diode-connected transistor)

Discrete current mirror for half an amp, what can go wrong...

[rstofer]

A lamp, just like your picture shows!

6W at 12V is 500mA, so try a car sidelight or indicator bulb...

Thanks for responding! I couldn't seem to find any lamps that are higher than 500mA. The best I could find was a 1W 12V LED.

A simple current mirror can be made with 3 parts: a transistor, a resistor, and a diode (or diode-connected transistor)

The other obvious answer is of course just a 24 ohm resistor.

Thanks for the info! I'll have to study about current mirrors now, and I'm sure that'll be useful to me in the future. But I think the obvious answer of just using a resistor was what I was looking for. My mind wasn't working well because I'm tired of concentrating on circuits since yesterday.

Tail light/brake light bulb should be available at an auto supply store.
5 each 1/2 Watt 100 Ohm resistors in parallel - 600 mA

[Jay112]

A lamp, just like your picture shows!

6W at 12V is 500mA, so try a car sidelight or indicator bulb...

Thanks for responding! I couldn't seem to find any lamps that are higher than 500mA. The best I could find was a 1W 12V LED.

A simple current mirror can be made with 3 parts: a transistor, a resistor, and a diode (or diode-connected transistor)

The other obvious answer is of course just a 24 ohm resistor.

Thanks for the info! I'll have to study about current mirrors now, and I'm sure that'll be useful to me in the future. But I think the obvious answer of just using a resistor was what I was looking for. My mind wasn't working well because I'm tired of concentrating on circuits since yesterday.

Tail light/brake light bulb should be available at an auto supply store.
5 each 1/2 Watt 100 Ohm resistors in parallel - 600 mA

Thanks! I actually could have used the advice about putting them in parallel, because I forgot to match the power rating of the resistor! I got my dosage of magic smoke for the day.

[Chris Mr]

I have a reel of nichrome wire I use to make up dummy loads.

If you wrap it round a sheet of something you can use a croc clip to vary the resistance.

In your case though I would use a light bulb - diagnostics