Diode test and identify

Started by Steve Wolf in sci.electronics.basics2 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.basics5 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


1N5817 schottky

Started by John in sci.electronics.basics11 years ago 8 replies

Hello, I'm about to make a wideband rf sniffer using an op amp and a simple detector front end feeding a capacitor and one of the inputs to...

Hello, I'm about to make a wideband rf sniffer using an op amp and a simple detector front end feeding a capacitor and one of the inputs to the op amp. I could bias the diode near conduction if it will help. I have to hand a 1n5817 schottky diode which is claimed to have a low forward voltage drop. While it's not exactly a signal diode will it do the job? Our local electronics store (Map...


zener diode info and ID ?

Started by robb in sci.electronics.basics10 years ago 12 replies

i have a suspect zener diode from a PS . Zener, because the PCB says it is (ZD901) it looks like a small signal diode and it has a 16 and 2...

i have a suspect zener diode from a PS . Zener, because the PCB says it is (ZD901) it looks like a small signal diode and it has a 16 and 2 printed on opposite sides. to test/replace --- the 16 is for ? volts ? and the 2 is ? *OR* are the ###s short hand for some other 1N4### value ? and the best test is to measure V across it ? thanks for any helpful replies, robb


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


Trying to Find Class 1 Laser Diode

Started by Patty in sci.electronics.basics9 years ago 20 replies

I need to make a laser pointer for a profoundly disabled friend. It needs only to point 3 inches so I'm looking for a Class 1 laser diode that...

I need to make a laser pointer for a profoundly disabled friend. It needs only to point 3 inches so I'm looking for a Class 1 laser diode that will be safe for him despite his erratic movements. Any help in locating a Class 1 laser diode that would be appropriate would be REALLY appreciated. Thanks. Trish


Microwave diode?

Started by DaveC in sci.electronics.basics11 years ago 22 replies

Have simple detector circuit that specifies 1N21B diode. That diode is 20-plus years old and obsolete. Looking for current equivalent, possibly...

Have simple detector circuit that specifies 1N21B diode. That diode is 20-plus years old and obsolete. Looking for current equivalent, possibly (but not necessarily) smt. Are these useable in place of a 1N21B for 2.4 GHz detection?: Suggestions welcome. Thanks, -- DaveC me@bogusdomain.net This is an invalid return add


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...


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

Started by Patrick Chung in sci.electronics.basics6 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


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


power diode testing?

Started by mynick in sci.electronics.basics9 years ago 6 replies

Tested each of diode pair fch20u10 with analog ohm-meter: directly-open but with bigger direct voltage conducts, inversely- resistance of 40...

Tested each of diode pair fch20u10 with analog ohm-meter: directly-open but with bigger direct voltage conducts, inversely- resistance of 40 ohms! but I suspect it is ok or not because tested an ok mur1620 and it showed 100ohms I guess those fast power diodes should not show inverse resistance of Kohms?


schottky diode question

Started by tempus fugit in sci.electronics.basics11 years ago 10 replies

Hey all; I'm planning on using a MAX4622 CMOS switch in a circuit I'm building. On p.7 of the data...

Hey all; I'm planning on using a MAX4622 CMOS switch in a circuit I'm building. On p.7 of the data sheet (http://datasheets.maxim-ic.com/en/ds/MAX4621-MAX4623.pdf), it says: "If power-supply sequencing is not possible, add two small signal diodes in series with the supply pins and a Schottky diode between V+ and VL" I've read a bit about Schottky diodes, and I see that there are severa...


model parameters in LT Spice

Started by Michael Robinson in sci.electronics.basics9 years ago 19 replies

I've just started using the free version of LT Spice and haven't had a problem doing simulations as long as the components are in the library. ...

I've just started using the free version of LT Spice and haven't had a problem doing simulations as long as the components are in the library. Now I need to do a simulation using a component that's not in the LT Spice library, the 1N4001 diode. Somebody sent me the model for the 1N4001, which is great. So my question is, after you put a diode symbol in the schematic, how do you assign...


Question about LM334 current source

Started by wthurt in sci.electronics.basics10 years ago 3 replies

I would like to use the LM334 with 9V batteries to produce an approximate 3mA constant current through a diode. But I am a little confused by...

I would like to use the LM334 with 9V batteries to produce an approximate 3mA constant current through a diode. But I am a little confused by the device schematic. This device has three leads (V+, ADJ, and V-) --- I have put a 25 ohm resistor between ADJ and V- to select the current I want. But I'm not sure where to put my diode? where does the constant current flow?


Types of diode-connected BJTs

Started by C Egernet in sci.electronics.basics10 years ago 19 replies

What are the relative merits of diode-connecting a BJT by shorting base and collector (using B-E junction) versus shorting base and emitter (C-B...

What are the relative merits of diode-connecting a BJT by shorting base and collector (using B-E junction) versus shorting base and emitter (C-B junction)? Na=EFvely, I have assumed that one always uses the B-E junction but then I saw this post from s.e.d by Phil Hobbs: > BFT25A C-B junctions are at least as good as 2N4117As as diodes. > > Cheers > > Phil Hobbs What gives? Chr


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.basics6 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...