ECS1• 12
SETUP AND TESTING
Plug a 9V battery into the connector. You should hear some chirps coming out
of the speaker. Turn R9 to adjust volume. Now turn R7 slowly to get the pitch
that you think sounds most like a cricket. In addition you can remove one or
both capacitors C9 and C10. This will change the sound more, but will also
reduce volume. When you get the sound the way you like it, you need to cali-
brate the ECS1 so that it will chirp to the right frequency. The cricket-chirp-to-
temperature rule is: Count the number of chirps in 15 seconds and add 40.
This gives the temperature in degrees Fahrenheit. Well, it gives the approxi-
mate temperature. No one is claiming that a cricket can replace a Fluke™
temperature probe. However, the cricket chirping does increase very linearly
with frequency and is plenty accurate enough for an interesting fireside con-
versation starter. Anyway, when properly adjusted the ECS1 will duplicate the
accuracy of a cricket over a typical cricket’s chirping temperature range of
about 55°F to 90°F or more. To calibrate your ECS1 you need to turn it on and
set R2 such that the chirp frequency is 2.13Hz, or 128 chirps per minute at 72°
F. If you have an oscilloscope you can measure the frequency of pin 3 on U1
and adjust R2 until it is exactly 2.13Hz. If you don’t, you can use the counting
method; it will just take a little longer. To do this, count the number of chirps in
a minute. Now divide by 4 and add 40. This is the temperature in °F. If this
value is woefully wrong then you must adjust R2. If your ECS1 gives you a
temperature that is too low, adujust R2 clockwise. If it gives you a temperature
that is too high, adjust R2 counter-clockwise. You should start by measuring
the resistance across R2 and turning it until the value is about 30.2K ohms, or
about 2/3 of a turn counter-clockwise. When you get your cricket calibrated,
put it somewhere interesting and listen to it peep peep until it drives your
friends and family mad.
TROUBLESHOOTING GUIDE
This is a pretty easy kit to troubleshoot. Most problems can be found using a
clear head and a logical approach. Make sure U1, U2, and U3 are in the right
way. Then check Q1, D1, D2, D3, D4 for proper orientation. Check all parts for
correct value and placement, and look over your solder joints to be sure that
there are no cold solder joints, no solder bridges, and no open connections.
Check for clipped off lead ends that may have lodged between the connec-
tions causing a short. Have a friend look over your work; sometimes another
pair of eyes will catch mistakes that we miss. Make sure your regulator is put-
ting out +5VDC and that you have that voltage on each of the 555 IC s at pin
8. If all else fails check the warranty instructions on the inside back cover of
this manual for details on sending the kit in for repair.
(23 stránky)
Manymanuals.com
Manymanuals.de
Manymanuals.fr
Manymanuals.it
Manymanuals.pl
Manymanuals.cz
Manymanuals.es
Manymanuals-pt.com
Komentáře k této Příručce