Electronics Forum / Basics / January 2006

I have been trying to make a +15 0 -15 regulated power supply. I have
been using a pair of LM 723C with TIP 3055 and TIP 2955 (I think I have
the correct number here) as the pass transistors (NPN and PNP) for the
+ve and -ve sides repectively. I am interested in a dual supply ...

I have a 40VCT .25A transformer and I'm wondering what those numbers mean..
does the 40VCT mean 40VAC from the center tap? If so across its full
secondary its 80VAC?  and the .25A means that it can handle at most .25A
across its secondary coil(since its a step down from 120VAC the ...

could you tell me how to do AC open loop LDO simulation properly?
how the inputs should be polarized when i open the loop to pass device
give me the current i want to.
when i do transient and op analyses, everything is ok. vref is connected

Take advantage of a great deal

I'm building a PSU and I've got a 40VCT @.25A transformer. I want to have
two outputs of +V1 and -V2 volts... i.e., two outputs that are adjustable.
I've done it for the +V already using the LM317T and a circuit that they
have in there data sheet... I get from 1.25 to 30V...

"Rich Grise"
** The only thing that's fundamentally wrong here is that you're
troll feeding that psychotic fuckwit  -  Rich Grise.
 Killfile the prick  NOW.

This could be OT, but I'm posting here to get replies with no
baggage....
I have a relay in my boiler which buzzes/arcs  I'm trying to diagnose
the fault, probably in my wiring.  What conditions (eg shorting) would

Hi, I'd like to preface this post by saying I know alot about software
and little about electronics. Please speak slowly and use small words.
I salvaged a stepper motor for a project I'm working on (it says Epson
Precision(H.K.) LTD. 8310  770173) and I would like to be able to

I have searched on Google for hours, but have not been able to find any
updated circuit info on the newer Kodak displosable camera circuits
that have an LED for the ready light instead of the neon tube.
On my last camera harvest, the majority of the 100+ cameras I got were

You have seen the commercials on TV about the new flash light that
never dies and needs no batteries?
Anyone here have one?
I don't have one but I was wondering about the bulb.  It seems likely

I've built a 418MHz RF receiver into a Radio Shack project box together
with a couple of relays.  When I push one of the button on the
transmitter, one of the relays closes.
My intent is to wire this into the doorbell circuit, so I can ring the

i have a v belt driven woodlathe that i want to change to variable
electronic speed control. i dont know if it is single or 3 phase . runs on
240 v. i know enough about electronics to follow a schematic but not enough
to know what i am looking for. i tried google but got lost in ...

I cant seem to find these transistors and resistors
4.7K Ohm 1/4-Watt Carbon Film Resistor 5% tolerance
NPN 2N222 rated 600mW - Case Type TO-92
i have looked maplin, rs and ebay anyone know a uk website i can get

Sorry if this sounds like a simple stupid question.
How do I charge a Sub-C Battery?
Do I need a special battery charger, or will most normal battery
chargers charge a Sub-C Battery?

Hello members, I am confused whether PCB (Printed Circuit Board) also
known as Polychlorimated Biphenyls can cause cancer. Dear members any
comment on this ?
Thanks