QUESTIONS & ANSWERS
■ FIGURE 9.
components, so “old tech” is my only
present option (iron soldering only).
Note: The pot for speed control
can be a mini PCB mount because
once it’s set, it won’t be accessible
without opening the unit. The
sequence should repeat until
switched off manually.
— Geoff Mayberry
AAll Electronics does not recognize that part number, but Newark has four units in stock and
similar devices are made by other
manufacturers. However, I did not
find any in stock. The LED is surface-mount but easily hand-solderable.
The operating condition is 3.2V, 350
mA (1.12 watts).
The circuit in Figure 7 consists of
a 555 oscillator driving a 4017
counter/1 of 10 decoder. Feedback
to the reset pin limits the output of
the 4017 to one of six. Since only
one LED is on at any one time, only
one current limiting resistor is
needed. The ZVN4210A is rated 100
volts so it can be connected to 12
volt power and survive the load
dump transient, but the CMOS ICs
have to be protected by R4 and D7.
Figure 8 is the Parts List.
I made a layout (Figure 9) to see
if the parts will fit in a 2-1/4” circle. It
does fit — just barely — and I have
the Gerber files. The heatsinks for the
three watt LEDs are all connected
because it gives greater heat
dissipation and the cool white LEDs
are isolated; some others are not
isolated and should be used with
EARN MORE MONEY
Get your dream job!
Be an FCC Licensed
Make up to $100,000 a year and
more with NO college degree
November 2011 27
Call now for FREE info
ext. 209 Or, online:
Warren Weagant’s FCC License Training
1;0;;#P Y;;;;;;;%FQU;;;;;;;t;;4BV TBMJUP;;$";94966
Please rush FREE info immediately!
Learn Wireless Communications and get your
“FCC Commercial License” with our
proven Home-Study Course!