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Diodes for dummies: a TO-220 question

Redboy

Redboy

a few good watts
I took a stab at wiring up a full wave bridge using discrete TO-220 diodes, and I appear to have failed miserably...

I've never used the durn things before, and I have an inkling of where I might have gone wrong. I pulled the image below from the Cree datasheet.

Q: Is the mounting tab actually connected to the cathode end? :scratch2:

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A:Yes.

You can solve this problem by getting TO-220 mounting kits which include the mica insulating washer and hardware to isolate the TO-220 diodes from the chassis. They used to sell these at Radio Shack. Don't know if they still do.

Result, no more blown fuses.

Dave
 
Daggummit!

:)

Thanks for the help! Radio Shack was a no go, but I just placed an order online.
 
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Here's a link to the mounting kit you need from Mouser

Be sure to use the non conductive spacer under the screw head.

There are also silicone thermal pads that can be used in place of the mica insulator and thermal paste.

These might look better in your mysterious project (in another thread) than having thermal paste all over your nice looking heat sink
 
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According to RadioShack.com, they still have these TO-220 mounting kits in stores. The stock number is 276-1373.

You probably talked to one of their dumb ass employees. They have lots of those in stock.:D

I used to like Radio Shack. I really did. Now it's usually a waste of time, unless you want a cell phone.

Dave
 
I didn't actually talk to anyone in RS - I've learned that most of the employees there have no idea what all those little bits n' pieces in the parts bins are for!

I ordered from Digikey, as they're in MN, super fast, and their shipping charges are much lower than Mouser. I bet I'll receive the stuff tomorrow.

After consulting with a local buddy who's much better versed in this stuff (he spotted my boneheaded mistake right away), I'm going to forgo the thermal paste this time: this gadget's running low voltages and fairly low current, so the diodes will barely break a sweat.
 
Redboy said:
I didn't actually talk to anyone in RS - I've learned that most of the employees there have no idea what all those little bits n' pieces in the parts bins are for!

...snip
Click to expand...

Something I learned waaay back in the 1970's. Funny thing happened after I was literally insulted in one- the company got sold and restructured. An example of bad Karma. To this day I will only use them as a last resort, and even then- only the franchised ones.
 
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