Archive of the former Yahoo!Groups mailing list: MOTM

Hello to the group!

I was looking at the 800 modification on Dave Bradley's web site
(www.hotrodmotm.com/800_mods.htm) and was thinking about the discussion
that took place about Paul's reluctance to include LED's because of the
noise introduced into the system.

My thought here was to place a transistor in series (emitter/collector)
with the LED (a 2N2222 would probably do). The base of the transistor
could be set high with a toggle switch to allow the LED to function
during trouble shooting, and the take the base low for playing,
eliminating the noise issue. The 470 ohm resistor is probably sufficient
for current limitation through the transistor.


+15 -----\/\/\/------∗ ∗-------|
10K on \ off |
\ |
∗ |
| B |
|--------| ----- |
| | |---|>|---/ \--| |
|--|\ | | LED C E | |
-| \ | 470 | NPN | |
| >--|----\/\/\/--|--|\ | |
+| / -| \ | |
-------|/ | >----------| |
+| / |
|--|/ |
| |
|----------------------|
|
grnd ---
-


This would suit my style of studio work, as once the patch was
functioning correctly, the LED becomes unnecessary (except for those who
like watching the blinky lights). A circuit could even be devised to
allow one switch to perform this globally for all 800's in the system.

Note: this is an idea, NOT a tested circuit.

Any thoughts? Is this interesting or a total waste of time?

Scott