Search found 2220 matches
- Sun Aug 24, 2014 9:53 pm
- Forum: General Discussion
- Topic: Schematic diagram for Tektronix probe, please ?
- Replies: 11
- Views: 11538
Re: Schematic diagram for Tektronix probe, please ?
I am afraid that you are SOL on what you want to do here. The P6105 is a garden variety passive probe with all their shortcomings. Basically a series 9 meg resistor shunted by a 10 pf capacitor at the tip. The comp box at the other end has a variable capacitor to ground that is adjusted in conjuncti...
- Sat Aug 23, 2014 9:23 pm
- Forum: General Discussion
- Topic: Trying to find / download a service manual...
- Replies: 10
- Views: 14725
Re: Trying to find / download a service manual...
I downloaded a manual a few months ago from one of those sites. You jump thru a bunch of hoops to confuse you and then finally there appears a giant DOWNLOAD button. without going any further I gladly pressed it. Yeah, I got my manual and along with it a host of viruses. For one, it completely took ...
- Sat Aug 23, 2014 9:09 pm
- Forum: General Discussion
- Topic: Cure for failing remote controls...
- Replies: 6
- Views: 7142
Re: Cure for failing remote controls...
I have had that phenomenon happen more times than I'd like to remember. I think its a chemical change in the molecular structure perhaps speeded up by heat and humidity. One thing seems certain - its a "Death Knell" that eventually kills it even if you perform temporary maintenance on it. ...
- Sun Aug 03, 2014 9:07 pm
- Forum: General Discussion
- Topic: Boda antenna construction
- Replies: 4
- Views: 6919
Re: Boda antenna construction
I have seen Vertical Dipoles described in that way.
- Sun Jun 15, 2014 9:17 pm
- Forum: General Discussion
- Topic: Old Magazines
- Replies: 2
- Views: 8993
Re: Old Magazines
Great Find Steven! Don't know where to start first
- Wed May 21, 2014 9:18 pm
- Forum: General Discussion
- Topic: Why won't my motor spin?
- Replies: 17
- Views: 14481
Re: Why won't my motor spin?
Well the mystery is solved and I thought I should share this with you before I close out this post. I did some experimenting with the one shot timing which slowed down rotation speed. At 50 RPM the motor worked perfect just as the circuit was designed to do. Decreasing the one shot timing and conver...
- Tue May 20, 2014 7:52 pm
- Forum: General Discussion
- Topic: Why won't my motor spin?
- Replies: 17
- Views: 14481
Re: Why won't my motor spin?
Hey John and Len Looked at this problem from a different angle and need some backup opinions for my theory. As stated I scoped a consequent drive pulse for each coils energizing and all this time was assuming that the Hall detector was located on that pole piece. but in actuality, the detector could...
- Tue May 20, 2014 11:48 am
- Forum: General Discussion
- Topic: Why won't my motor spin?
- Replies: 17
- Views: 14481
Re: Why won't my motor spin?
John The coils appear to fire one at a time. And to reinforce that action (and again this is just my take on it) If you look at either Hall device you will note either transistor base connected to opposite poles of the hall device. Since each hall will see a positive and negative field from the roto...
- Mon May 19, 2014 9:42 pm
- Forum: General Discussion
- Topic: Why won't my motor spin?
- Replies: 17
- Views: 14481
Re: Why won't my motor spin?
Lemp Qx base drive pulse from Hall device is sequential with Coil x current. does not appear to be any overlap from coil to coil current. Will try to upload current and revised circuit. Revised circuit is a monostable ring style generator with tickle pulse start. All connections and timing match up ...
- Sun May 18, 2014 9:54 am
- Forum: General Discussion
- Topic: Why won't my motor spin?
- Replies: 17
- Views: 14481
Re: Why won't my motor spin?
Yes John the motor runs very free. Manually rotated it in small increments before power up and still nothing. Out of desperation, used a power drill with a rubber snubber attached and made gentle contact with the motor shaft to get it up to speed-still nothing! Would a simplified schematic help?
- Sat May 17, 2014 9:34 pm
- Forum: General Discussion
- Topic: Why won't my motor spin?
- Replies: 17
- Views: 14481
Why won't my motor spin?
Have a blower motor in a piece of equipment that refuses to start at power up about 20% of the time. Did some investigation and here is what I found: It is a four pole brushless motor with two imbedded hall devices placed 90 degrees apart in close proximity to the axis of the shaft in which has a PM...
- Thu May 15, 2014 7:41 pm
- Forum: Nuts & Volts Magazine Discussions
- Topic: Zeener Diodes in Parallel: 72 Watt Power Supply, May 2014
- Replies: 2
- Views: 23335
Re: Zeener Diodes in Parallel: 72 Watt Power Supply, May 201
Are these already built into one of the off shelf items or are they reader built added circuitry. I see no mention of them in the parts list. All good arguments here and the only thing I could add is a reduced source impedance of the zener circuit, which like all other suggestions would be out of th...
- Sat May 03, 2014 9:12 pm
- Forum: Up For Grabs
- Topic: Commercial Intercom Components---Long Gone!
- Replies: 10
- Views: 25828
Re: Commercial Intercom Components
I may have use for a power amp Len. I have a large pond with an even larger Frog problem(thousands and thousands). I have tried everything to rid them, but to no avail. My last ditch thought is an underwater transducer kicked by a heavy power amp. Problem is I have not quite finished with preliminar...
- Tue Apr 08, 2014 7:58 pm
- Forum: General Discussion
- Topic: Opinions please
- Replies: 5
- Views: 3959
Re: Opinions please
OR--- Maybe 'Lytics with the negative polarity stripe. I cant envision any use for diodes here and especially in that size.
- Thu Mar 13, 2014 9:38 pm
- Forum: General Discussion
- Topic: Readout window
- Replies: 3
- Views: 2784
Re: Readout window
Hey, thanks a bunch Externet. Did not check Digi or Mouser as did not know how they were categorized. Can even get the bezels too-cool. Will order some soon.