User`s manual

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wire or other igniters. The Eggtimer is capable of handling up to 30v, so you can ignite even an
Aerotech Copperhead igniter with it, assuming you have a strong enough battery (i.e. 14.4v LiPo
battery).
Channel B Deployment (CHB) - Two solder pads, marked “+” and “-“ for connecting an
electric match or other low-to-medium current device. Deployment delay/altitude is
programmable. Maximum 8A current, 30 VDC, 60 W. You can also connect the input for a
standard analog hobby servo to the “+” terminal (along with a 39 ohm ¼ W resistor in parallel)
for non-pyro deployment.
Channel B Battery (BCHB) – Separate battery terminals for the Channel B deployment. This is
provided in case you want to use two different batteries for Main and Channel B; this allows you
to mix pyro outputs and servos, since servos generally use 6v or less. If you are using both
Channel A (Main) and Channel B, and they are OK on the same battery (i.e. they’re both either
servos or both igniters), then you can jumper the BCHA and BCHB terminals together: + to +,
and – to - .
AUX1 Output – The AUX1 output turns ON (+V) for two seconds, at nose-over detect. It can
be used to provide redundancy for the CHB channel in drogue (nose-over) mode, or it can be
used to trigger a drogue parachute if CHB is being used in Airstart mode. This is an unbuffered
(logic-level) output, a high-current driver circuit will be required to trigger a load of over 20 mA
or over +V (typically 3V-4V). See the Eggtimer web site (www.EggtimerRocketry) for details.
AUX2 Output – The AUX2 output “shadows” the function of the CHA (MAIN) deployment
output. It can be used to provide redundancy for the CHA output. Note that if CHA is disabled
(set to “0”), the AUX2 channel will also be disabled. This is an unbuffered circuit, see the
description of AUX1 for details.
AUX3 Output – The AUX3 output turns ON (+V) when a landing has been detected (AGL of
less than 30 ft for at least 5 seconds), and stays on until the Eggtimer is reset. This is an
unbuffered output, see the description of AUX1 for details.
Data Port – 6-pin FTDI-compatible standard header connector for connecting the USB-serial
data cable for programming and downloading data, and also for connecting a telemetry device
such as an RF serial transmitter (not included).