Search found 1581 matches

by dyarker
Mon Nov 02, 2020 8:34 pm
Forum: General Discussion
Topic: Power Supply for mains circuit _linear or switch mode
Replies: 7
Views: 587

Re: Power Supply for mains circuit _linear or switch mode

The load is 15 ohms at 120 Volts and 12 amps DC.
Does not compute!

120V / 12A = 10 Ohms

Or, if the 15 Ohms is correct, then 12Amps is wrong; like JWax said.
by dyarker
Mon Nov 02, 2020 2:13 pm
Forum: General Discussion
Topic: Power Supply for mains circuit _linear or switch mode
Replies: 7
Views: 587

Re: Power Supply for mains circuit _linear or switch mode

I have never of anything needing 110VDC at 12 Amps. (probably why no vendor makes one)

And not safe unless isolated from mains.

What is the load?
by dyarker
Mon Nov 02, 2020 10:11 am
Forum: General Discussion
Topic: Power Supply for mains circuit _linear or switch mode
Replies: 7
Views: 587

Re: Power Supply for mains circuit _linear or switch mode

How are you regulating the output to 110VDC? The peak of 110VAC is 155V. At no load that is what the filtered DC will be. As load current increases, output ripple voltage increases as the filter capacitor supplies the current between the input voltage peaks. The input current is zero till the input ...
by dyarker
Thu Sep 10, 2020 7:39 am
Forum: General Discussion
Topic: ADR421 Vref IC Low Short-Circuit Current!
Replies: 10
Views: 867

Re: ADR421 Vref IC Low Short-Circuit Current!

Not getting 10mA (max) into a load is a problem. It looks like IC fails in this respect.

Getting a smaller short circuit current is a good thing. Why are you worried that? When output voltage is forced to zero (by short) the IC probably limits the current so it does not destroy itself.
by dyarker
Tue Sep 08, 2020 2:17 pm
Forum: General Discussion
Topic: ADR421 Vref IC Low Short-Circuit Current!
Replies: 10
Views: 867

Re: ADR421 Vref IC Low Short-Circuit Current!

Where are you seeing 27mA in the spec.
Last item in specs for each part number. In this case on page 5 of 24. And resolved subject line problem in post 2.
by dyarker
Mon Sep 07, 2020 8:11 pm
Forum: General Discussion
Topic: ADR421 Vref IC Low Short-Circuit Current!
Replies: 10
Views: 867

Re: ADR421 Vref IC Low Short-Circuit Current!

Now I missed a line on spec sheet - Load Regulation, Conditions column; which shows 0ma to 10mA.

Where did you get the IC? Discount places sell parts that failed some test but still function.
by dyarker
Mon Sep 07, 2020 3:13 pm
Forum: General Discussion
Topic: ADR421 Vref IC Low Short-Circuit Current!
Replies: 10
Views: 867

Re: ADR421 Vref IC Low Short-Circuit Current!

The spec sheet title is ADR421. The "BRZ" on your parts might mean low power. A 1k load is a ridiculously heavy load for a precision reference. It is not a power supply regulator. -------------------------------------------------------- Yes, probably not oscillating. Did you place 2 small capacitors...
by dyarker
Mon Sep 07, 2020 2:31 am
Forum: General Discussion
Topic: ADR421 Vref IC Low Short-Circuit Current!
Replies: 10
Views: 867

Re: ADR421 Vref IC Low Short-Circuit Current!

The spec sheet I'm looking at https://www.analog.com/media/en/technical-documentation/data-sheets/ADR420_421_423_425.pdf says 27mA is typical, not minimum. There is no minimum. So, the IC you got limits to a lower current to protect itself when a short is detected. A short is an error condition. Why...
by dyarker
Tue Jul 28, 2020 7:33 pm
Forum: General Discussion
Topic: Paralleling circuit breakers
Replies: 13
Views: 1480

Re: Paralleling circuit breakers

Nonsense, he said non equal current rated breakers.

And even if they were equal breakers, and the wires were just large enough not to overheat, they are not a load balance resistor.
by dyarker
Fri Jul 24, 2020 1:17 pm
Forum: General Discussion
Topic: Paralleling circuit breakers
Replies: 13
Views: 1480

Re: Paralleling circuit breakers

The resistances of the breakers is not directly related to current ratings. So, for example, with a 60A load the 15A breaker may pass 20A. The 15A breaker will trip. That leaves the 50A breaker with the whole 60A, it will trip too. Equal rating, same part number breakers will share the load more eve...
by dyarker
Thu Jun 18, 2020 10:16 pm
Forum: General Discussion
Topic: 4G LTE Interference on OTA Antenna TV
Replies: 16
Views: 1779

Re: 4G LTE Interference on OTA Antenna TV

Please read the posts before answering! This discussion was about towers on insulators. Which means RF hot tower. A hot tower needs a spark gap for lightning protection without shorting the signal. My mention of spark gap a couple posts back was for hot tower, obviously a non-hot antenna support tow...
by dyarker
Thu Jun 18, 2020 11:24 am
Forum: General Discussion
Topic: 4G LTE Interference on OTA Antenna TV
Replies: 16
Views: 1779

Re: 4G LTE Interference on OTA Antenna TV

The tower you say is 600ft not 2000ft. It supports other antennas so is unlikely insulated at the base. The mountain it is on is not relevant.

The big tube likely is waveguide, or coax.
by dyarker
Thu Jun 18, 2020 10:23 am
Forum: General Discussion
Topic: 4G LTE Interference on OTA Antenna TV
Replies: 16
Views: 1779

Re: 4G LTE Interference on OTA Antenna TV

A 1/2 wave antenna for an AM broadcast station could more than 400 ft.

(is 2000ft an over estimate?)
by dyarker
Thu Jun 18, 2020 10:06 am
Forum: General Discussion
Topic: Voltage and Current
Replies: 5
Views: 857

Re: Voltage and Current

Electron flow, outside the source - electrons flow from the negative terminal through the external circuit to the positive terminal of the source. Inside the source the electrons are forced toward the negative terminal. The extra electrons at the negative terminal is what made it negative in the fir...
by dyarker
Wed Jun 17, 2020 5:11 am
Forum: General Discussion
Topic: Multisim simulation error in High-pass Filter Circuit Design
Replies: 2
Views: 572

Re: Multisim simulation error in High-pass Filter Circuit Design

Active filter? If yes, what cutoff/rolloff of the amplifier?

(images didn't work - had to ask)