X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=doc%2Ftelemetrum.inc;fp=doc%2Ftelemetrum.inc;h=9562d99459b9e6794906dd25038660e3ac321bf3;hb=8cf466d7a767a20387a8d9d6ec81ee00af3fe4a7;hp=0000000000000000000000000000000000000000;hpb=c1ca80318102af122cb7b5380331e37795280761;p=fw%2Faltos diff --git a/doc/telemetrum.inc b/doc/telemetrum.inc new file mode 100644 index 00000000..9562d994 --- /dev/null +++ b/doc/telemetrum.inc @@ -0,0 +1,68 @@ +== TeleMetrum + + image::telemetrum-v1.1-thside.jpg[width="5.5in"] + + TeleMetrum is a 1 inch by 2¾ inch circuit board. It was designed to + fit inside coupler for 29mm air-frame tubing, but using it in a tube that + small in diameter may require some creativity in mounting and wiring + to succeed! The presence of an accelerometer means TeleMetrum should + be aligned along the flight axis of the airframe, and by default the ¼ + wave UHF wire antenna should be on the nose-cone end of the board. The + antenna wire is about 7 inches long, and wiring for a power switch and + the e-matches for apogee and main ejection charges depart from the + fin can end of the board, meaning an ideal “simple” avionics + bay for TeleMetrum should have at least 10 inches of interior length. + + === TeleMetrum Screw Terminals + + TeleMetrum has six screw terminals on the end of the board + opposite the telemetry antenna. Two are for the power + switch, and two each for the apogee and main igniter + circuits. Using the picture above and starting from the top, + the terminals are as follows: + + [options="header",grid="all",cols="2,3,10"] + |========================= + |Terminal #|Terminal Name|Description + |1 |Switch Output |Switch connection to flight computer + |2 |Switch Input |Switch connection to positive battery terminal + |3 |Main + |Main pyro channel common connection to battery + + |4 |Main - |Main pyro channel connection to pyro circuit + |5 |Apogee + |Apogee pyro channel common connection to battery + + |6 |Apogee - |Apogee pyro channel connection to pyro circuit + |======================== + + === Using a Separate Pyro Battery with TeleMetrum + + As described above, using an external pyro battery involves + connecting the negative battery terminal to the flight + computer ground, connecting the positive battery terminal to + one of the igniter leads and connecting the other igniter + lead to the per-channel pyro circuit connection. + + To connect the negative battery terminal to the TeleMetrum + ground, insert a small piece of wire, 24 to 28 gauge + stranded, into the GND hole just above the screw terminal + strip and solder it in place. + + Connecting the positive battery terminal to the pyro + charges must be done separate from TeleMetrum, by soldering + them together or using some other connector. + + + The other lead from each pyro charge is then inserted into + the appropriate per-pyro channel screw terminal (terminal 4 for the + Main charge, terminal 6 for the Apogee charge). + + === Using an Active Switch with TeleMetrum + + As explained above, an external active switch requires three + connections, one to the positive battery terminal, one to + the flight computer positive input and one to ground. + + + The positive battery terminal is available on screw terminal + 2, the positive flight computer input is on terminal 1. To + hook a lead to ground, solder a piece of wire, 24 to 28 + gauge stranded, to the GND hole just above terminal 1. +