Hi guys,
I am new to electronics and I am looking for a device which can ignite rocket igniters via a countdown timer.
Here is the project I want to do but have no idea where to start
What equipment will I need? I need an Arduino board but does it have to be a certain type of Arduino board?
can all the equipment required for this project be purchased through littlebird?
He has a link to the project page:
http://arduining.com/?s=launcher
You could use just about any arduino even the pro mini if you wanted to take up less space. A quick search and you could probably get 90% of the components used on littlebird.
so the equipment I need which can be purchased through littlebird would be:
Arduino UNO R3 (recommended for beginners with Arduino)
7 segment Serial Display
10k potentiometer
yellow arcade button
piezo buzzer
protoboard / protoshield
missile switch cover
LED lights
10k ohm resistors
N-channel Fets
9V batteries
tupperware box or 3D printed case for the electronics
Don’t forget your other resistors (100ohm, 240ohm and 2.4kohm), capacitor (22uF) and 5V relay. Note that he uses an n-channel transistor (2n2222A) for the relay driver but you could use a mosfet like you said. Does that all make sense?
there are a few parts you have listed which I am unsure of their purpose and I need to know why they are necessary.
The capacitor acts like a small battery correct?
the n-channel transistor what does this actually do?
the 1N4001 what does this do?
the 5V relay what does that do? switch currents?
do all the negative wires connect to just 1 GND slot or do I use a separate GND slot for each jumper wire?
I wish this schematic included a diagram of how to setup the jumper wires.
These resistors with varying Ohms… why not use a standard 460ohms resistors for the entire circuit board? I know this sounds like a stupid question but I don’t know electronics well enough to answer this question. Appreciate all the help.
I’m glad you’re asking mate, that’s how you learn! So capacitors typically do act as ‘batteries’ but in this case it is used as a coupling capacitor which more or less means it improves the response of the speaker.
As for the transistor, when the arduino makes pin 7 go from low(0V) to high (5V) it turns on the transistor which means that current will flow through the relay coil turning it on which completes the safety switch circuit. Now the transistor is used because the arduino can’t directly supply enough current to turn on the relay itself (from memory I think each arduino pin can only supply 20mA whereas some relays need more than this). The diode in this case is used as a flyback diode, the link explains it pretty well. Without it you could end up damaging the transistor.
All the grounds can just be connected together and to a single GND pin on the arduino, but not the ignitor circuit part.
The resistor values used are for particular reasons such as letting enough current to the speaker so its loud enough, and limiting the current to the transistor so it turns on.
I would make the circuit in something like this,
https://123d.circuits.io/lab
That way you can really poke around and see what is happening. You can even use the code listed to simulate the whole thing.
