Rocket Recovery Timer 2 UPDATE

Discussion about deployment systems including altimeters, timers, air speed flaps, servo systems, and chemical reactions.
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Rocket Recovery Timer 2 UPDATE

Post by Jamie5335 »

Hello All,

I apologise for my absence on the forum, I have had a few exams at school to deal with by now I can relax/further advance in my Rocketry!

Previously I made a statement about the Rocket Recovery Timer 2 (RRT2) in its early stages of development and basic info about the timer is available in that topic or my website.

I can now show you the final design that I intend to etch next Wednesday (25th of June):
3d model.jpg
3d model.jpg (24.35 KiB) Viewed 31 times

What differs from the previous design is listed below:

- I have replaced the standard through hole resistor pads with custom pads NOT because I don't intend to use them it is just I want to mount them differently so they can save space on the board.

- I have removed the programming socket from the board and plan to make that externally available to plug into a set of headers to the right of the board to save space.

- I have added a Piezo buzzer to get an auditory response to what state the timer is in (armed, setting delay etc).

- I have added in two 220nF Capacitor to help reduce electrical noise from the Servo.

- I have added two Electrolytic Capacitors and two decoupling capacitors to help keep a more consistent input voltage of 3.3 volts for the board to work with as previous testing shows voltage spikes from the 4.2V Lipo.

- I have replaced the large Variable Resistor with a smaller rotary Potentiometer to save space.

- I now plan to use ultra low voltage Servos as most can only run of a minimum of ~4.8 volts. A Transistor will be used to help boost the current for the Servo.

Here are the components that have arrived so far, I am waiting on the Potentiometer from Hong Kong!
DSC02391 - Copy.JPG
DSC02391 - Copy.JPG (45.55 KiB) Viewed 31 times
VR.JPG (27.95 KiB) Viewed 31 times
Question about electrical noise:

I don't know much about it!! For any of you electronics experts out there do you know if adding the 220uF Capacitors will help eliminate the noise?? Should I have the + and - rails as wide as possible??

Will Solder over the Summer holidays, still need to finish writing the code!

Any thoughts or comments please feel free!

The board is around 80mm by 30mm as it is difficult to see from the 3D model- this is small enough for my purposes but as I have said this is part of a continuing development cycle of Rocket Recovery Timer's- this is the second in the series.

Cheers Jamie B.
JSB Rocketry

Jamie Bignell,
Somerset UK

"The important thing is to know how to take all things quietly" -Michael Faraday.