Step 8: Test SCR, connect cathode.

Now connect the yellow (negative) lead to the Cathode. The flashlight bulb should remain off.  If it comes on, you have a shorted SCR.
<p>Hello ,<br>I made a tester about 30 years ago using resistors for the load and LED's for the indicators . Mine used 4 &quot;C&quot; batteries to get 6 volts , had a normally open switch to trigger the gate , a normally closed switch in the anode/cathode circuit , also a normally open switch with a load resistor and LED for a battery test . To use the tester , connect the 3 leads to the SCR , press the GATE switch and it should turn on . press the other switch to turn it off . I used it many years doing industrial electrical maintenance . I retired a year ago and as far as I know the electricians at the plant are still using it .</p>
I have a quick question I follwed your instructions but once i ge to the stp about removing the gate once removed the bulb turns off. And also if I touch the cathode lead to the anode it produces a bright blinding light. It should not do this. Help?
That is normal for the SCR tester. It is as if you are closing the switch on the flashlight.
That's a great experiment! i have a 3W 160 lumens <a href="http://www.gadgettown.com/Flashlights/">LED Flashlights</a>, is it suitable to experiment?
You can also test Mosfets and IGBTs if you add a 9 volt battery inseries. I have instructions at this <a href="http://home.comcast.net/~botronics/TestingSCR.pdf">link</a>. You can test leds too. Its a multipurpose tester and even a flashlight!<br />
I recently obtained a couple large SCRs that look just like the ones inyour instructable. They're labeled &quot;GE C55B&quot;, but I couldn'tfind any information or datasheet for them. Do you have a similar model,and if so, do you have or know where to obtain datasheets for these?<br /><br />Thanks for any help you can provide!<br />
I don't know about the GE SCR, but here is a <a href="http://www.pwrx.com/pwrx/docs/t700.pdf">link</a> for he datasheet on the big one shown. You can get the Powerex scrsfrom Galco.<br />
Thank you for a well-done, useful Instructable; even though I do notwork with large SCR's.&nbsp; <br />
Thank you.&nbsp; Here is a youtube video of it working.<br /><object height="344" width="425"> <param name="movie" value="http://www.youtube.com/v/zxIu1KIUZMk&amp;hl=en&amp;fs=1&amp;" /> <param name="allowFullScreen" value="true" /> <param name="allowscriptaccess" value="always" /> <embed allowfullscreen="true" allowscriptaccess="always" height="344" src="http://www.youtube.com/v/zxIu1KIUZMk&amp;hl=en&amp;fs=1&amp;" type="application/x-shockwave-flash" width="425" /></object><br />

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Bio: I like to tinker and experiment with electronics, robotics, programming, and photography. Along with my latest interest in Steampunk.
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