Search found 10 matches

by rckbrwn
Wed Feb 27, 2002 4:57 pm
Forum: General Discussion
Topic: Battery Acid Leak on Circuit Board
Replies: 7
Views: 1751

Re: Battery Acid Leak on Circuit Board

Many small cells of that type are alkaline based. A weak acid is required to nutralize the electrolyte. Then, rinse repeatedly with distilled water. However, circuit boards absorb this conductive mix and as a result become permanently conductive. The board may or may not ever work again depending on...
by rckbrwn
Thu Feb 21, 2002 5:25 pm
Forum: General Discussion
Topic: momentary signal to a shift register - how?
Replies: 9
Views: 2245

Re: momentary signal to a shift register - how?

ac couple the transition from the switch to the 555.<p>Rick
by rckbrwn
Thu Jan 24, 2002 6:17 pm
Forum: General Discussion
Topic: Need info on PIC16C73A
Replies: 3
Views: 1038

Re: Need info on PIC16C73A

I heard once upon a time that someone was able to erase otp's with xrays. I have wondered if it would be possible to erase them by placing the part in a high voltage field while all the pins are shorted together. Can HV induce cell leakage without destroying it? I have considered using some old epro...
by rckbrwn
Sat Jan 19, 2002 5:12 pm
Forum: General Discussion
Topic: Chip Info
Replies: 2
Views: 1056

Re: Chip Info

A google search on LB8070 found 2 places selling them. Both places sell that p/n for less than $2 US. Seems too cheap for such a part. But it might be the one.
http://datadart.com/al/semi.html
http://members.aol.com/semiconpart2/sempart12.htm<p>Rick Brown
by rckbrwn
Thu Jan 10, 2002 7:30 pm
Forum: General Discussion
Topic: Can you help me find one?
Replies: 5
Views: 2377

Re: Can you help me find one?

Finding that exact xfmr will be nearly impossible at an affordable price. A power transformer from an old hobby type oscope would probably take care of the crt. Consider rewinding the old xfmr. Carefully disassemble and count the turns from each winding. Duplicate the 3 low voltage windings for +/- ...
by rckbrwn
Tue Jan 01, 2002 2:21 pm
Forum: General Discussion
Topic: digital ohm meter schematic
Replies: 3
Views: 1998

Re: digital ohm meter schematic

Harbor Freight has 3 1/2 digit multimeters for about $5.<p>Rick
by rckbrwn
Tue Jan 01, 2002 2:16 pm
Forum: General Discussion
Topic: Simple Metal Detector
Replies: 2
Views: 1517

Re: Simple Metal Detector

Try these links for metal detector theory and schematics. The second one is quite simple in spite of it alledged capabilities and is one I plan to try. The schematic on the web page is corrupted, but the author will email you a complete schematic if you ask. No details for the coil are given, but th...
by rckbrwn
Sun Dec 30, 2001 2:20 pm
Forum: General Discussion
Topic: ultrasonic cleaners
Replies: 11
Views: 2865

Re: ultrasonic cleaners

A few years ago, popular electronics or radio electronics had a construction article for an ultrasonic cleaner. Heathkit made one also. You might be able to track down a manual reprint for it.<p>Rick
by rckbrwn
Tue Dec 18, 2001 9:13 am
Forum: General Discussion
Topic: Surplus BS2's For Sale
Replies: 2
Views: 1528

Re: Surplus BS2's For Sale

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by toejam:
what's a bs2?<hr></blockquote><p>basic stamp 2<p>Rick
by rckbrwn
Mon Dec 17, 2001 6:57 pm
Forum: General Discussion
Topic: Surplus BS2's For Sale
Replies: 2
Views: 1528

Surplus BS2's For Sale

I have for sale, some new unused BS2's that I aquired in lot of surplus components. $35 ea. Contact me off list at [email protected]<p>Rick Brown