Electronics Forum / Basics / December 2007

Did you see my post with the constant current circuit?
I'm also a ham, call sign KF2HI
I got my extra back when you had to copy code at 20 wpm to get it.
I was looking at your call sign.  Is that British?

I'm planning on building a battery radio kit, that I plan on making
into an AC set through the use of trnsforers.  I've found a
transformer that gives out 9 volts, but I need to add a resistor to
step it down to about 1.5-2 volts.  What value and wattage must this

would it be usefull to use two similar 1n4148 diodes to sense air
tempreature differential?
my application is to use one diode at floor level and another diode at
ceiling level to detect gross temperature

I'm planning to build a crystal radio similar to the one linked to at
the bottom of this post, but the specs call for a 30-160 pf tuning
capacitor, all I can find is a 60-160 pf cap.  Will this still work?

yes, i did google and i got a gaggle of garbage a few good links
and somw great stuff with dead or deadend links.
a product called **UMPS** came up alot and i saw a screen for it
then all the references eventually go back to

My head is absolutely spinning after trying to find an easily
available (i.e., multiple source) "generic" LDO voltage regulator to
power a PIC and a few components.  Just too darn many choices.
The specs are:

As a professional Mutilayler PCB Manufacturer, Supplier and Exporter
with a Factory in Taiwan, our main products include Printed Circuit
Board, PCB Assembly, PCB Board, Multilayer PCB and PCB Design, PCB
Layout Service. We provide you with high quality Mutilayler PCB and

Michael Lalonde almost got killed by a wild dog in Peru during an
important business meeting in a sad mood and decided to sleep it off
which completely freaked him out he jumped out of the way as the roof
collapsed and to the disappointment of some he killed the bad guy and

this is a read-only maskable 32K words x 8bit  ROM  (compatible
with 27cxxx  ROMs)
This ROM chip was subjected to momentary 32 V DC on the Vcc  pin.
Now (no surprise)  it behaves as rather continuously and

my microcontroller board has installed a 23256AC (i.e. 27c256
style) ROM chip with 8031 MCU...
I traced the ROM chip's pins to be (reasonably) sure that i was
selecting a correct/compatible eprom chip setup for ***reading***

I made a tiny amp for my electric guitar with the LM386 chip and a
small speaker
http://www.national.com/ds/LM/LM386.pdf
I hooked it up just like the basic circuit in the datasheet, grounding

I have a motor home which has the main battery for the engine and an
auxiliary battery to supply the lighting etc in the living area. With
the ignition off a relay switches the auxiliary battery to supply the
living area but when the vehicle is running the relay connects the

Akai EA-M830 Manual
Does anybody know where I can get a free operating manual for an Akai
EA-M830 Sound processor please?
PDF format would be fine.

Is it 2.2 mV/C?

Hello, I am in search of some help.
I know the basics about sound and such, but none of the really
technical stuff.  I am looking to do something that seems almost
impossible to me to do properly without messing anything up.