TO-3P Insulator cover  - Page 1
Forum section: electronics / repair

author: daveyk
author_rank: Frequent Contributor
timestamp: September 20, 2020, 12:28:07 am
content: Is there any place in the US that I can purchase: TO-3P Insulator cover - TOP3 - L:28.5mm - W:17.5mm - H:5.8mm - 0.8W/mK - 4kVHere's what they look like:https://www.ebay.com/itm/TO-3P-Insulator-cover-TOP3-L-28-5mm-W-17-5mm-H-5-8mm-0-8W-mK-4kV/312796561381?hash=item48d420bfe5:g:2IEAAOSwwlVdnJ7q$10+ Plus high shipping.I can't find them in the USA in EBAY, DIGIKEY, or MOUSER.Thanks a bunch!

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 20, 2020, 12:41:30 am
content: At a glance, doesn't seem to be much selection, but this is a match and quite available, nice:https://www.digikey.com/product-detail/en/t-global-technology/THINC33-TO247-28-5-17-5-5-8-0-3/1168-1957-ND/3878146Tim

author: daveyk
author_rank: Frequent Contributor
timestamp: September 20, 2020, 12:49:55 am
content: Thank you! I searched Digikey and couldn't find anything. I didn't know what to search for I guess - lol; thank you.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 20, 2020, 01:03:39 am
content: Yeah... I've ran across them before, not sure how many there are. If there are other types or brands, they aren't listed under any descriptive labels.Tim

author: David Hess
author_rank: Super Contributor
timestamp: September 20, 2020, 09:45:22 pm
content: When you need an insulated cover for a TO-3 power transistor, then you really need it. I had a ground wire fall down behind a 12 volt 50 amp power supply and it touched the case of the TO-3 driver transistor which resulted in blowing out the low current control winding on the transformer.

author: daveyk
author_rank: Frequent Contributor
timestamp: September 21, 2020, 01:32:53 pm
content: In the case of this switching power supply, the main filter capacitor after the switching transformer most likely shorted (it is now 100% open, high ESR, no capacitance reading), took out the rectifying diode (600v inverse voltage, I think), and the main switching FET 2SK2601. Compared to another working supply, that transformer looks a little brown (over-heeated). It is probably bad, but I still want to try to replace the cap, diode and switching FET (which I needed that insulating sleeve for), more or less for shits and grins to see if I could fix it.The particular power supply is the only one ever tested for use in that UT system. Others may work, but you go to pay attention to noise radiation. I can only find that power supply used now. So I order a couple and I order all the caps to re-cap them before putting them in to use. I ordered 10 of those rare insulating sleeves just in case they tear taking the supplies apart to re-cap them.

author: Grandchuck
author_rank: Super Contributor
timestamp: September 21, 2020, 03:24:26 pm
content: Would something such as described in the attached link be a possibility?https://www.alliedelec.com/m/d/e4e619c16107fbf1651a92ccad8e4f4b.pdf

author: daveyk
author_rank: Frequent Contributor
timestamp: September 21, 2020, 07:59:51 pm
content: I just ordered 10 of these for 40 cents each:https://www.digikey.com/product-detail/en/t-global-technology/THINC33-TO247-28-5-17-5-5-8-0-3/1168-1957-ND/3878146Now based on your heat shrink suggestion, I don't think so. In addition to insulation, it has to have heat transfer parameters. These "hoods"/"covers" are made from that blue heat transfer tape.Dave