Q&A
■ WITH RUSSELL KINCAID
In this column, I answer questions about all
aspects of electronics, including computer
hardware, software, circuits, electronic theory,
troubleshooting, and anything else of interest
to the hobbyist. Feel free to participate with
your questions, comments, or suggestions.
Sendallquestionsandcommentsto:
Q&A@nutsvolts.com
WHAT’S UP:
Join us as we delve into the
basics of electronics as applied
to every day problems, like:
✓Variable Timer.
●✓Solar Cells.
✓PCB Layout Programs.
VARIABLE TIMER
QI need a timer to charge
small rechargeable batteries.
I need outputs of 1, 2,
4, 8, and 16 hours. I have
a 1, Pole 5, throw switch for time
selection. I can do all the peripheral
work such as relays and LEDS, etc. I
just need the outputs. I already have
the power supply and transistors
for charging and discharging the
outputs at about one amp. I have
4060s, 4040s, 555s, other ICs, and
the resistors and capacitors.
— William D. McMurray
AI don’t know why you want
a timer because a battery
can be left permanently
connected to a good charger
■ FIGURE 1
22
June 2007
