Diode test and identify

Started by Steve Wolf in sci.electronics.basics5 months ago 8 replies

trying to fix AC/DC power plug. I have a Diode that says: GW327 SR560 I THINK this is a Schottkty Diode. Setting meter to Diode test,...

trying to fix AC/DC power plug. I have a Diode that says: GW327 SR560 I THINK this is a Schottkty Diode. Setting meter to Diode test, Im getting, 1.71 Forward and Reverse .171. Normally on diode I know you should get 1 on reverse Are these readings allowable or is the Diode Bad. Thanks.


Two diode vs four diode rectification

Started by Peter Percival in sci.electronics.basics8 months ago 31 replies

What is the advantage of a four diode bridge full-wave rectifier over a two diode full-wave rectifier. There must be some, else why accept the...

What is the advantage of a four diode bridge full-wave rectifier over a two diode full-wave rectifier. There must be some, else why accept the extra cost? -- "He who will not reason is a bigot; he who cannot is a fool; he who dares not is a slave." - Sir William Drummond


PING: Kevin Aylward, Diode Model Question

Started by Jim Thompson in sci.electronics.basics5 years ago 8 replies

Hi Kevin, Suppose I wanted to model JUST the capacitance portion of a diode? No DC current, etc. The equation "fold-over" at VD~FC*VJ...

Hi Kevin, Suppose I wanted to model JUST the capacitance portion of a diode? No DC current, etc. The equation "fold-over" at VD~FC*VJ looks to be PITA to implement. Maybe you know of a way to trick a full diode model into not doing its DC thing ?:-} ...Jim Thompson -- | James E.Thompson | mens | | A...


driving a 1000 mW laser diode

Started by Ingmar Webb in sci.electronics.basics2 years ago 1 reply

I want to power a laser diode (the kind used for engraving) in a portable device for short periods with a 9V battery. The laser diode comes in a...

I want to power a laser diode (the kind used for engraving) in a portable device for short periods with a 9V battery. The laser diode comes in a tube with a focusing lens and trailing wires, and the spec says 5V 1A. This diagram seems to be the standard circuit for driving these. The LM317 spec says Vout is 1.25V above Va and it needs 3V of headroom. ---------- +9V----o-----...


Diode Lead Length

Started by Anand P. Paralkar in sci.electronics.basics7 years ago 9 replies

Hi, I would like to use the 1N5283 diode in a certain application. Like some other applications in power electronics, this diode datasheet...

Hi, I would like to use the 1N5283 diode in a certain application. Like some other applications in power electronics, this diode datasheet too mentions a certain Lead Length to be maintained. (See http://www.datasheetcatalog.org/datasheet/motorola/1N5298.pdf) Could someone please explain this? Why does this distance have to be maintained? (Its got to do with the thermal character...


pin diode

Started by Anonymous in sci.electronics.basics4 years ago 8 replies

Hi, What is the difference between Light Detector Resistor and a pin diode? And which one is better to use for solar tracking purposes and...

Hi, What is the difference between Light Detector Resistor and a pin diode? And which one is better to use for solar tracking purposes and why? For example LDR: http://www.digikey.com/product-detail/en/PDV-P8104/PDV-P8104-ND/480611 PIN DIODE: http://media.digikey.com/pdf/Data%20Sheets/Everlight%20PDFs/PD204-6C.pdf mel


diode, rectifier dead?

Started by Anonymous in sci.electronics.basics12 years ago 12 replies

Can anyone confirm whether following microwave oven components are dead -diode hvr1x8019:tested with analog ohm meter-short both...

Can anyone confirm whether following microwave oven components are dead -diode hvr1x8019:tested with analog ohm meter-short both directions -rectifier 2x062h 8025:..open in both directions tnx


Inductor current can't be suddenly cutoff if no freewheel diode is attached

Started by Patrick Chung in sci.electronics.basics7 years ago 3 replies

Inductor current can't be suddenly cutoff if no freewheel diode is attached. New tutorial...

Inductor current can't be suddenly cutoff if no freewheel diode is attached. New tutorial is ready http://www.cirvirlab.com/index.php/tutorials/105-r-l-circuit-with-mosfet-as-switch-and-freewheel -diode.html and online simulation http://www.cirvirlab.com/simulation/r-l_circuit_with_mosfet_as_switch_and_freewheel_diode.php


A capacitor/resistor question

Started by Anonymous in sci.electronics.basics7 years ago 2 replies

Greetings All, In the book "Electric Motors and Control Techniques" a circuit is illustrated that is for the dynamic braking of a squirrel cage...

Greetings All, In the book "Electric Motors and Control Techniques" a circuit is illustrated that is for the dynamic braking of a squirrel cage motor. This circuit discharges a capacitor through the field windings to slow the motor. The capacitor is connected across the AC power to the motor in series with a 50k resistor and a diode. I under stand why the diode is there. The resistor must be...


Re: Automotive alternator windings & rectifier

Started by Mike Cook in sci.electronics.basics7 years ago 4 replies

> > http://www.autoshop101.com/forms/alt_bwoh.pdf > > > > has photos of an alternator with 4 connections for windings (each of 3 > > ...

> > http://www.autoshop101.com/forms/alt_bwoh.pdf > > > > has photos of an alternator with 4 connections for windings (each of 3 > > phases + common), > > Not one of the pages shows four connections brought out from the > windings. Photo on p. 18. > > and the 8 diode rectifier. > > I don't see any 8 diode rectifier. Photo on p. 25. Note callouts for 6 diodes but you can see 8 round


Why won't my meter check this?

Started by Anonymous in sci.electronics.basics6 years ago 38 replies

I have a DVM made by Extech that has the diode check function. When checking a regular diode the function works. But when I try an LED it shows...

I have a DVM made by Extech that has the diode check function. When checking a regular diode the function works. But when I try an LED it shows open both ways. And when I try to measure resistance the meter shows open both ways. Is it possible that the LEDs just need more current before than the meter provides they will conduct? Thanks, Eric --- This email is free from viruses and malwar...


simple oneshot

Started by George Herold in sci.electronics.basics6 years ago 15 replies

Hi all, OK a silly basic question. I'm doing some digital stuff. I wanted a one shot to reset some things, but didn't want to put in an...

Hi all, OK a silly basic question. I'm doing some digital stuff. I wanted a one shot to reset some things, but didn't want to put in an entire chip (74HC123.. or whatever the number is.) So I just used a cap, resistor, diode and inverter. https://www.dropbox.com/s/flnonc9rgwmerhw/DSCF0082.JPG Is this OK? Thanks, George H.


How to slow down RPM of miter saw?

Started by John Doe in sci.electronics.basics5 years ago 48 replies

The motor runs on standard USA 120 V 60 Hz, 14 A, at 5500 RPM. What's the easiest way to slow down the RPM? What about simply adding a...

The motor runs on standard USA 120 V 60 Hz, 14 A, at 5500 RPM. What's the easiest way to slow down the RPM? What about simply adding a diode in series on the power cord? Any advice, references, and links would be appreciated. Thanks.


finding laser diode parameters

Started by Chris in sci.electronics.basics4 years ago 14 replies

I made a bulk purchase of red laser diodes off Ebay. There are three bags together unmarked. 25 of them are 3.3V., another 25 are 4.5V and the...

I made a bulk purchase of red laser diodes off Ebay. There are three bags together unmarked. 25 of them are 3.3V., another 25 are 4.5V and the other 25 are 5V. But like I say they're not labelled so I don't know what spec correpsonds with which batch. They're all in brass hosts with adjustable lenses. Is there a simple way to tell which is which - establish safe working current and volt...


Ta Da!

Started by Jim Thompson in sci.electronics.basics6 years ago 4 replies

Ta Da! Title of Invention: METHODS SYSTEMS AND DEVICES FOR MINIMIZING POWER LOSSES IN LIGHT EMITTING DIODE DRIVERS Filing Date: May 28,...

Ta Da! Title of Invention: METHODS SYSTEMS AND DEVICES FOR MINIMIZING POWER LOSSES IN LIGHT EMITTING DIODE DRIVERS Filing Date: May 28, 2014 ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Sys...


simple oneshot(2)

Started by George Herold in sci.electronics.basics6 years ago 23 replies

Hi all, OK a silly basic question. I'm doing some digital stuff. I wanted a one shot to reset some things, but didn't want to put in an...

Hi all, OK a silly basic question. I'm doing some digital stuff. I wanted a one shot to reset some things, but didn't want to put in an entire chip (74HC123.. or whatever the number is.) So I just used a cap, resistor, diode and inverter. https://www.dropbox.com/s/flnonc9rgwmerhw/DSCF0082.JPG Is this OK? Thanks, George H. (This didn't appear the first time I posted it... trying ag...


Passive f to 2f converter

Started by George Herold in sci.electronics.basics7 years ago 14 replies

I got a request for a f to 2f converter for our lockin. http://www.teachspin.com/instruments/signal_processor/ (Freq = 3 - 3k Hz. ) (Well a...

I got a request for a f to 2f converter for our lockin. http://www.teachspin.com/instruments/signal_processor/ (Freq = 3 - 3k Hz. ) (Well a crappy pic, but I wanted to show that it has a filter module. (It stinks signal wise too, the photographer didn't like the second bnc cable from the reference output.)) Passive would be the simplest. I thought of a diode rectifier, and when my bo...


zener diode operating current

Started by panfilero in sci.electronics.basics8 years ago 3 replies

I want to use this 100V zener, and I'm trying to figure out how much current it draws when it's turned on, on the datasheet I see Vz "working...

I want to use this 100V zener, and I'm trying to figure out how much current it draws when it's turned on, on the datasheet I see Vz "working voltage" is between 95V-105V with the condition Iz = 1 mA does that mean that as long as I make sure the zener is capable of getting at least 1mA that this will conduct when I go over 100V? here's the zener I'm looking at http://www.nxp.com/doc...


Generating this negative pulse?

Started by Terry Pinnell in sci.electronics.basics11 months ago 15 replies

I have a couple of simple 555 monostables, the first to delay the triggering of the...

I have a couple of simple 555 monostables, the first to delay the triggering of the second. https://www.dropbox.com/s/6uboy3fgd0ixhxa/GenerateNegPulse-1.jpg?raw=1 But I'm struggling to extract the brief -ve pulse required for the Main mono. I thought it would prove simple. But bread-boarding various combinations of R, C, diode and NPN or PNP transistor has so far not yielded a winning comb...


White Noise Source

Started by Chiron in sci.electronics.basics8 years ago 72 replies

I need a source of white noise (audio). It doesn't have to be perfect. I seem to recall that you could use a zener diode as a white noise...

I need a source of white noise (audio). It doesn't have to be perfect. I seem to recall that you could use a zener diode as a white noise source. Is this true? Are there any other possibilities? I anticipate using a 9-V battery for my power, and a few transistors to amplify the signal to drive earphones. You may ask, "why the heck would he want to do that?" Good question: http:...