Electronics Forum / Basics / July 2008

Having found dual op amp packages around a fifth the price of
comparable single packages from online distributors, I think i'll go
for the double.
(BTW, I'm using supply of +16, and ground).

I built an astable multivibrator with blinking lights (much simpler
than using a 556!), as a test for a circuit that will use a power
transistor (or MOSFET) to pulse a transformer primary for future
experiments.

I hope to run a 40' pair of cables from my power supply (Mastech
3010E-3) to my charger (Thunder Power 1010C). Here's what I've been
thinking, I could use any thoughts you might have on the right way to
go about this. The Mastech push 60v/10a or 30v/20a and the TP 1010c

The subject describes pretty much my question. I have been spending
several days trying to debug a circuit, only to find that it wasn't my
fault:
I have a normal (pretty cheap) switch-mode plug-pack power supply

Apologies in advance if this is a dopey question, but, when it comes to
recharging batteries, and using a solar cell to do that, what I've been
assuming, based on th info that peopl ehere have kindly provided, and also
that I've foind on-line, is that teh mA output of the solar ...

Is it standard that a TO-220 transistor package is, with the tab up,
with the markings facing you, Base, Collector, Emitter?  (for example,
on the TIP31A)
I noticed the TO-92 2N3904 I have is (with the markings facing me) E B

I would like to data log commanded spark events for my vehicle.  It
uses a Distributorless Ignition System which consists of a engine
control computer, a control module, and a coil pack.  The coil pack is
fed 12v and has control wires.  When a control wire is brought to

i am working on a project called less current consuming led lamp,and
the major idea of this project is less consumtion of current and
compact in size.so i have planned to take out transformer ,which
consume lot more space,so i want a help from u guys how to isolate the

Since the 9v battery supply is quickly used up, I am using a ac
battery eliminator/wall wart to run the Led timer.
Although the eliminator provides the needed 12v to 15 v, it also
changes the 50 hz dramatically to several khz.

My company wants to buy an oscilloscope.  The scope that meets our needs is
around $7,000.  I am sure we can save much money if we buy a PC-based unit,
like Picoscope.  Do you have experience with PC based scopes?  Do you
recommend them for serious work?

I wanted to take a minute to say THanks! to:
Tom Biasi
John Fields
Peter Bennet

I've got a toroidal core, and I'm planning on winding it with pulsed
12VDC on the primary, and want to get out 50V on the secondary, center
tapped so I can get +/- 25V.
The 12VDC will be provided from a 555 switching a power MOSFET at 10

Hello again.  I'm still working on my tube testing project.  I have been
trying to determine the transconductance of the 6EJ7 tubes I have.  Here is
my setup:  Plate and screen grid at 240 vdc.  Heater at 6.3 vdc.  Grid 3
tied to cathode.  Control grid at -3 vdc tied to cathode ...