62 June 2017
READER - TO - READER TECHFORUM
>>> QUESTIONS
Miniature Parts Needed
I’ve been tearing down Seiko
solar quartz watches in search of
small efficient engines to power
miniature robots. Can anyone
recommend a source for additional
components, such as miniature axles
and wheels?
#6171 Naja Heilmann
Norcross, GA
What To Do With Leaded Solder
I have a bunch of 2 lb rolls of
leaded solder that I no longer plan to
use, given the availability of lead-free
solder. How should I dispose of the
solder? Is it considered hazardous
waste due to the lead?
#6172 Derek Raya
Westlake, OH
Sequential Turn Signals
The simple way to do an
automobile three-light sequential turn
signal is to let the blinker turn on bulb
#1 and then the circuit will do #2 and
then #3; not a problem.
The problem is the brake lights
that use the same filament in the
bulbs. Hit the brakes so left and right
will sequence once then stay lit,
unless you hit the brake again.
Same with turning. One side
sequences and if you hit the brake,
the other side will sequence once
and then stay lit while the turning
direction is still sequencing. However,
if you hit the brake, both sides will
sequence once and then stay lit.
Proper function can be
accomplished because aftermarket
kits are available that do it correctly.
Unfortunately, they are very
expensive.
No matter what I think of, I
cannot come up with any logic circuit
that would prevent the brake indicator
from sequencing once, i.e., blinker
ON-OFF 12V, brake ON 12V; brakes
only, ON 12V both sides.
Any simple ideas? Hope I do not
need to program an IC. Guess I can
always learn at 72 years old. Started
reading N&V when it first began. Love
it.
#6173 Daniel Zielinski
Port Saint Lucie, FL
Unknown Power Supply For
Monitors
I have three mini monitors
(Figure 1) but no power supplies,
and would like to know what power
supply to use. I have tried one of the
three monitors using a 12 VDC at
500 mA supply and it came on for a
nanosecond.
Since then, I have tried the same
monitor several more times with the
same supply, and also using my car’s
battery, my lawn tractor’s battery, and
even purchased and tried a 12 VDC
at 1A supply all with the same results.
What is the power requirement
for such mini monitors? I don’t want
to burn any of them out using the trial
and error method.
#6174 M Williams
St John, IN
AQUABOT Pool Cleaner
A friend of mind asked me if
I could fix her “PoolRover” pool
sweeper. The timer does not work
properly.
The power supply/controller has
a big transformer and circuit board
inside, and for a lack of ID, has a bar
code P12909124848. I have looked
high and low for a schematic for this
unit, both with the manufacturer and
on the Internet, but have come up
blank. I started working on a start/
stop timer from http://ronj.eu5.org/
rt2.html.
Does anyone have any better
solutions? Timer on for 30 seconds
and off for two seconds, and back on
again.
#6175 Terry Arnall
Hayward, CA
>>> ANSWERS
[#1172 - January 2017]
Trainsformer Needed
I found a bargain at a local thrift
store and now have a 1959 Marklin
HO Scale train, cars, and track. The
set didn’t come with a transformer, so
I thought it would be a fun project to
build from scratch. Does anyone have
n FIGURE 1.
