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FrozenGate by Avery

IN4001 Question.

FWIW I picked up six 1N5404 diodes and two 1 ohm 10W resistors at rat shack for ~7 bucks last night to make my high current test load. By the time I figured in shipping from digikey RS was only a dollar or so more which is worth not waiting for shipping.
 





Ah well, these are pretty standard components to begin with.

You may have to be careful with the resistor though. Wire wound ones are usually okay as test loads for linear drivers, but their inductive nature may confuse switchmode drivers on a bad day.
 
SEVEN BUCKS for 8 parts?! Good hell does Radio Shack bend you over and ravage your bowels. I paid $11 for 100 of those 1N5406. Some 3W 1ohm 1% resistors would only be $0.83 each too. Shipping? Use the opportunity to buy other discrete parts so you never have to go looking again. I've got all the timers, PNP/NPN transistors, N-channel mosfets, and other stuff I'll ever need from my last order (Mouser in this case). Now I can make all the drivers I ever need. Hell, use the opportunity to buy higher tolerance parts while you're at it.
 
Buying parts individually is more expensive, its just the cost of picking them and everything. I just order them by the 100 or so too, since there is not really an experiation date on most components, and its handy to have a set of fairly standard stuff in stock.

10 watt resistors can be pretty expensive though, especially the non-inductive ones. I'd be inclined to use a small value for the resistor to reduce power dissipated in it.
 
Yeah I figure that any time I need to buy standard parts, I might as well buy a bunch of them because I'll inevitably need to use them some other day, and it's usually only a few bucks more for tens or hundreds more.

Radio Shack is my last resort, and I'll only ever go there if I need to have something fixed within the day, which is rare. Even then, I wouldn't trust them to even have the part I need; I'd rather go to the local electronics shop instead.
 
Rat Shack charges 1.69 (85 cents each) for a 2 pack. Digikey charges 40 cents each. The resisotrs were 90 cents each at RS and I didn't price them at Digikey but by the time I add another 3-4 bucks for shipping the cost is with a dollar or so of buying them at Rat Shack and I didn't have to wait for them to be delivered.

I'm with you though. I don't buy stuff at RS unless I have to. In this case it was a basically a push and the convenience of "get it now" instead of a week from now was worth the extra buck or so.
 
Sure, that is sometimes worth the extra bucks. I keep stocl odering from things like futurlec to keep the price of components to a reasonable level. I dont keep that much stock either, but things like 1-10-100-1k-10k resistors are things i buy in packs of a 100, as are 1n400x diodes etc.

Things like diodes, resistors and transistors have a pretty much unlimited shelf life, so its good to get them in large quantity. Things like electrolytic caps you don't want te be lying around for decades, so stuck up wisely on those!
 
LtKernelPanic said:
Rat Shack charges 1.69 (85 cents each) for a 2 pack. Digikey charges 40 cents each. The resisotrs were 90 cents each at RS and I didn't price them at Digikey but by the time I add another 3-4 bucks for shipping the cost is with a dollar or so of buying them at Rat Shack and I didn't have to wait for them to be delivered.
Click to expand...

Yes, it is true that sometimes the wait isn't worth it, but usually it is, especially if you don't need to get it next time. Anyway, what is purchased is purchased, but for future reference, also see what Mouser has as well when you're shopping around. Those diodes are a mere $0.15 in single quantities from Mouser.

I also recently discovered AllElectronics, which has some nice stuff too, such as perfboards, which are can be pricey to get at big shops like Mouser or Digikey (RS ends up being a decent place otherwise for perfboards).
 
Food for thought (and maybe mayhem...): In the long past we used to build RF dummy loads by paralleling 50 Ohm 1 Watt resistors in a can. I notice that most of the responders state that they usually have lots of 1N400x's laying around, and, lament the 1Watt dissipation limit of the 1N400x family,,, What about paralleling two or three 1N4001's for each single 1N4001 in your dummy load schematic? shouldn't change the voltage drops at each series junction and cann't change the circuit current,, and should increase the wattage capability of the load. twelve 1N4001's, two inparallel, in series with the next two in parallel,, and so on for six pairs, should give you a two Watt dummy load (yeah, I know, you can do better with 1N540x's, but what if all you have is 1N400x's). Just a thought...
 
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