12 June 2015
n WITH TIM BROWN
Help Finding Components
QIn reference to the article, “A Light House for Short People” from the 1968 Winter Edition of Electronics Experimenter’s Handbook by Popular
Electronics, I would like to build the lighthouse
for my granddaughter. Can you suggest some
easier to find components? I do have some neon
bulbs on hand.
— Dr. Jeff Helgoe
AI always enjoy looking back at where we have been in electronics, and Jeff’s article from the 1968 Experimenter’s Handbook is certainly
a stroll down memory lane for me. Popular
Electronics started their publication in October
1954 and continued under different publishers
until December 1999. I read some of my
uncle’s magazines from the late ‘50s and on my
migration to Nuts & Volts, I subscribed to Radio Electronics
which switched me over to Popular Electronics for a little
while in the late ‘90s before I was traded to Nuts & Volts
(in the end I think I got the best deal in the trade).
I redrew the 1968 lighthouse circuit (see Figure 1)
which used a nine volt transistor battery, GE Type C6U
SCR, 1N754 zener diode, NE- 2 neon lamp, 100 µF/12V
capacitor, 2. 6 KW resistor, and Argonne AR-110 transformer
wired to step up the voltage. I was able to locate suitable
parts for everything except the AR-110. From my past
experience, it is difficult at best to find information on
transformers. I suspect that the AR-110 with its 10 KW
primary and 16W secondary (25-to-1 turns ratio) was used
as an impedance matching transformer.
Argonne transformers still exist, but this particular
model apparently is obsolete (maybe one of our readers
can help here). Also, I could not find any transformers with
turn ratios as high as 25-to-1 (plenty of 10-to-1s). I suspect
the advent of ICs has something to do with this.
As they say, “necessity is the mother of invention” (in
my case, maybe desperation), so I came up with an LED
flasher using an NE555 IC timer which is shown in Figure
2. If you use a super bright LED, you may need to adjust
the LED’s current-limiting resistor to achieve the correct
current to give the best illumination. I show a six volt
power supply, but the NE555 can operate from 4.5V to
16V, so the nine volt battery may be a better choice than
four alkaline batteries.
Q & A
12 June 2015
In this column, Tim answers 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. Send all
questions and comments to: Q&A@nutsvolts.com.
• Help Finding Components
• Ice Melt Tape Controls
n FIGURE 1.
n FIGURE 2.