You haven't been very specific on what size rockets....
Good question BJ, I didn't think of that. I just applied the question to where I am right now.
Just a quick survey to see what folks need or want the most of these days in terms of 'lectronics...
Ok , a few easy questions for you if i may:Timers. My next cluster build will use timers for outboard ignition. Thermalite is getting too hard to find and mine is so old it's getting inconsistant. I already have the first 2 essentials, altimeters and a tracker.
My preferred method is g-switch. The acceleration should be maintained for about .25 seconds to be considered a valid launch. A break wire or pull plug would be my second choice. (Open circut to start timer.)Ok , a few easy questions for you if i may:
How do want to trigger the timer to start?
One. I would use multiple units when needed. My Motoreater design has 8 outboards so I could use as many as 4 units. For staging, the timer would be in the part of the rocket containing the motor(s) to be lit.How many timer/pyro outputs per unit ?
External battery, 3-12V. Isolate the electronics and include a cap or supercap to power the electronics during the pyro firing period. Regulate the battery voltage to whatever the electronics requires and use the battery direct to fire the pyros. Powerup debounce circuit should be able to handle long bounce times (1 second?) for users of the twist & tuck method.How do you want to power it ?
DIP switches, either straight binary or BCD. If a multiple channel timer, a separate switch for each channel is preferred. Read switch on powerup and store in memory. Do not rely on switches maintaining their state during flight.How do you want to program it?
Most useful would be 0-25.5 seconds for airstarts and staging, 0-255 seconds for recovery. If using BCD switches, 0-100 seconds. Another possibility would be to use one position for sec/.1 sec select and use the rest for 0-12.7 or 0-127 sec ranges.what time range per channel ?
I could use up to 4 channels but I prefer separate units for each. Then I can install only what is needed. You also need some kind of indicator so the user can tell if the unit is enabled. I prefer a beeper that can also be used to indicate continuity of the pyro like most altimeters use. (I know this will increase parts cost but it's worth it.)I think a universal timer for simple airstarts / staging / booster recovery needs at least 2 or 3 channels to cover all the uses i can think of- is there any point to more than that ?
Well, I'm about to start building what should be my Level 2 rocket - a Binder Samurai that Santa brought for Christmas (complete with the add-on ebay). Bought some extra couplers and tubes to modify it for dual-deployment - the plan is to fly it on H's and I's a bit to get used to dual deployment, then go for a J or a K sometime this spring/summer (if we ever get a high power field again for DARS, or I can make it down to Hearne or one of the other few places that fly high power in Texas in the summer).
Gots my MAWD and BigRedBee tracker transmitter already as well as some personal doorknob hanging alarms that I'll modify as a audible rocket finder thingie, so the "must have" electronics are taken care of, I think. May add a different altimeter (if Adrian gets the new altimeters done by then) or a BeeGPS transmitter.
But, what I'd really like to do is start carrying a small high def video camera on board the flights, and I dont' have one of those, yet, either!
There goes the tax refund!
I want the idiot-proof simplicity of the MAWD, the data download features of the Parrot, and the size/price of a RRC2 Mini. Where is THAT altimeter??? How about just the first two for under $125?
The answer to your last question is sitting on my workbench,
On the flip side, I think there are enough altimeters on the market already, and I'd be more interested in something not really available, like a lower-end, FCC-licenseless tracker of some kind.It looks like there's a definite trend forming- people seem to want more altimeters than anything else...