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References: [ +from:jpopelish@rica.net: 37 ]

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21. Re: [Amps] AC to DC (score: 1)
Author: John Popelish <jpopelish@rica.net>
Date: Sat, 28 Jan 2006 23:49:41 -0500
Yes, DC relays often have a thin film of nonmagnetic material between the coil core and the armature (the iron part it attracts), to keep the remnance from getting strong enough to hold the relay clo
/archives//html/Amps/2006-01/msg00662.html (8,074 bytes)

22. Re: [Amps] AC to DC (score: 1)
Author: John Popelish <jpopelish@rica.net>
Date: Sun, 29 Jan 2006 17:00:02 -0500
Any AC relay will hold in with some DC current that will not overheat the coil. DC is more efficient at producing attractive force than AC, because AC goes through zero twice a cycle. The big differe
/archives//html/Amps/2006-01/msg00702.html (8,114 bytes)

23. Re: [Amps] AC to DC (score: 1)
Author: John Popelish <jpopelish@rica.net>
Date: Sun, 29 Jan 2006 17:46:58 -0500
Sorry, I missed what you you were implying. Of course, any AC relay will pull in with a DC voltage lower than its rated AC voltage, and will almost certainly overheat if operated with DC voltage equa
/archives//html/Amps/2006-01/msg00706.html (7,537 bytes)

24. Re: [Amps] [BULK]Re: cathode to ground in tetrode amp (score: 1)
Author: John Popelish <jpopelish@rica.net>
Date: Mon, 30 Jan 2006 20:37:47 -0500
that). > He also has a choke in series with one of the attenuators resistors Is it possible that these chokes and capacitors you mention are pars in a peaking circuit, to push the frequency response
/archives//html/Amps/2006-01/msg00745.html (11,046 bytes)

25. Re: [Amps] [BULK]Re: [BULK]Re: cathode to ground in tetrode amp (score: 1)
Author: John Popelish <jpopelish@rica.net>
Date: Mon, 30 Jan 2006 21:01:18 -0500
Thanks for the link. Here are some of the numbers: The cathode LC resonance (just the 15 uH and .01 uF) produce an impedance peak at .41 MHz. That would notch out frequencies near that (a little lowe
/archives//html/Amps/2006-01/msg00748.html (10,456 bytes)

26. Re: [Amps] Queation on toroid core materials (score: 1)
Author: John Popelish <jpopelish@rica.net>
Date: Thu, 02 Feb 2006 11:54:21 -0500
First of all, there is some confusion using the word "saturates". Magnetic saturation involves a sharp drop in permeability as the magnetic flux passes through some large positive or negative value.
/archives//html/Amps/2006-02/msg00024.html (10,245 bytes)

27. Re: [Amps] transformer talk (score: 1)
Author: John Popelish <jpopelish@rica.net>
Date: Thu, 09 Feb 2006 13:16:29 -0500
To be more precise, the ratio of RMS AC input current to average DC output current of a rectifier with capacitor input filter is higher than the ratio of RMS input current to average DC output curren
/archives//html/Amps/2006-02/msg00208.html (8,871 bytes)

28. Re: [Amps] Choke-input with voltage doubler? (score: 1)
Author: John Popelish <jpopelish@rica.net>
Date: Thu, 09 Feb 2006 13:18:59 -0500
If you derate the transformer for output current, the chokes are not necessary. You can also lower the peak factor on the windings by adding a small inductance in series with the primary to spread ou
/archives//html/Amps/2006-02/msg00209.html (7,540 bytes)

29. Re: [Amps] Choke-input with voltage doubler? (score: 1)
Author: John Popelish <jpopelish@rica.net>
Date: Thu, 09 Feb 2006 18:35:36 -0500
That is one way to lower the peak current. But you get a slightly cooler transformer if you create the same heat in a resistor in series with the primary. During the peak currents, the transformer pr
/archives//html/Amps/2006-02/msg00212.html (7,892 bytes)

30. Re: [Amps] Choke-input with voltage doubler? (score: 1)
Author: John Popelish <jpopelish@rica.net>
Date: Thu, 09 Feb 2006 18:47:23 -0500
Too many unknowns to say exactly what derating factor is required. The goal is to keep the winding temperature in spec. Way too much. Something more like a millihenry or so, like what is used in big
/archives//html/Amps/2006-02/msg00213.html (8,709 bytes)

31. Re: [Amps] Need Multi position switch (score: 1)
Author: John Popelish <jpopelish@rica.net>
Date: Wed, 22 Feb 2006 18:00:26 -0500
Go to Digikey and enter part number 451-1027, 1 pole, 2 to 12 positions 1 amp at $8.25 ea. http://rocky.digikey.com/WebLib/ElectroSwitch/Web%20Data/C5%5EC6%20Series.pdf or EG1952, 1 pole, 2 to 12 pos
/archives//html/Amps/2006-02/msg00405.html (9,510 bytes)

32. Re: [Amps] Happy birthday to... (score: 1)
Author: John Popelish <jpopelish@rica.net>
Date: Thu, 16 Mar 2006 12:34:30 -0500
Think about elasticity and inertia. _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
/archives//html/Amps/2006-03/msg00469.html (8,111 bytes)

33. Re: [Amps] MW Oven Transformer question (score: 1)
Author: John Popelish <jpopelish@rica.net>
Date: Tue, 21 Mar 2006 11:17:51 -0500
When current passes through the secondary, that produces a magnetic field that bucks the field produced by the primary winding, causing the primary current to rise in unison with the secondary curren
/archives//html/Amps/2006-03/msg00569.html (8,713 bytes)

34. Re: [Amps] MW Oven Transformer question (score: 1)
Author: John Popelish <jpopelish@rica.net>
Date: Tue, 21 Mar 2006 11:42:38 -0500
If you have a supply of this kind of landfill, you might put two similar units side by side, wire the primaries in series (effectively halving the volts per turn, so eliminating the saturation proble
/archives//html/Amps/2006-03/msg00570.html (6,996 bytes)

35. Re: [Amps] MW Oven Transformer question (score: 1)
Author: John Popelish <jpopelish@rica.net>
Date: Tue, 21 Mar 2006 18:48:10 -0500
Normally, they are quite careful about connecting the laminations along only one side of a possible eddy current loop. So it makes little difference in the lamination loss. (Sorry about the email, To
/archives//html/Amps/2006-03/msg00579.html (8,410 bytes)

36. Re: [Amps] MW Oven Transformer question (score: 1)
Author: John Popelish <jpopelish@rica.net>
Date: Tue, 21 Mar 2006 19:39:55 -0500
The path of eddy current is around the flux path. There are not likely welds across both the outside of the laminations, and also across the laminations inside the hole, to complete a closed path tha
/archives//html/Amps/2006-03/msg00583.html (9,313 bytes)

37. Re: [Amps] Need some 220K 2 watt carbon resistors (score: 1)
Author: John Popelish <jpopelish@rica.net>
Date: Mon, 27 Mar 2006 11:19:52 -0500
I think there are some pulse power applications where the larger thermal mass of the resistive element in composition resistors absorb the pulses better. But high resistance value comp resistors don'
/archives//html/Amps/2006-03/msg00688.html (9,107 bytes)

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