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Help...IC id?

Hi: In preparing some Christmas lights I found a dead string. The light set contains a selectable flash sequencer to allow 6 different flashing patterns. The flash sequencer contains an IC that is stamped: RH 606, thats it. Any pointers on a replacement?

Also, it contains 4 transistors that drive each of the colored strings within the entire string. The transistors are marked: HFH 1225. Several google and IC specific sites yielded no useful information. Any help in finding replacements is appreciated.

I can probably use any generic switching transistor once I determine if they are PNP or NPN. (just havent had time to check the existing transistors, although I know that one is dead)

Thanks John

Reply to
John Hudak
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Are these the usual tree-type incandescent light sets? If so, they're likely to be small triacs or thyristors, not transistors, so a transistor type test is no good. Are they in TO-92 cases by any chance? Every multi-sequence Christmas light set I've seen uses a dedicated IC for the flash sequencer, (probably not possible to get a replacement except from manufacturer) which turns 4 triacs/thyristors on or off to switch the AC to the lights.

All you need to do is measure the current each light group uses, and select a triac/thyristor with a suitable current handling, allowing a comfortable safety margin. Some lights are directly mains voltage so you'll need to select a suitable replacement with that in mind. (ie for 220V use a 400V or better, for 120V use a 200V or better).Others use something like a 24V AC transformer, and just about any triac will handle that, you just need to worry about the current handling.

Another thing to consider is the gate sensitivity. If the IC drives them directly without a buffer it's likely they are the 'sensitive gate' variety. If you use a non-sensitive gate variety it won't work and could damage the IC.

Dave

Reply to
Dave D

yes

Yes, your right...I should have known better...

yes to-92

I figured as much...the lightset was in a GE box, but, it was made by GOKW in China...I *really* wish we would not off-shore all this stuff....but that is another rant...

Yes, that is direct enough to do...I would like to scope the thing but first I better draw a ckt dwg. The input side is a diode bridge directly across 120 VAC, one filter cap and then dropping resistors to the IC..as cheap and dirty as it can get.....and not even a fuse....since I realized this, I may just pitch them...too dangerous..I've seen too many semiconductors become wires, then fuses...

Yes the IC drives it directly.....I agree with you...Thanks for waking me up.....

Reply to
John Hudak

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