I have a Simple RF M4 Receiver ID:1096 that I want to control 2 small motors via 4 relays.
Here's the circuit I have in mind. Is it correct? I have left off the motor wires for clarity. Do I need to add any resistors or capacitors to this system with the relay coils?
Simple RF M4 Receiver connection question
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Re: Simple RF M4 Receiver connection question
What is the rating for the coils on those relays? If it is more than 20 mA or so, you will probably need a transistor to drive the coil. In any case, you will want to add a diode to each relay circuit to protect against the reverse voltage spike generated when the coil is de-energized. A typical circuit would be similar to the one here: http://makezine.com/2009/02/02/connecti ... o-arduino/
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Re: Simple RF M4 Receiver connection question
Nominal coil current is 89.3mA. Will probably need a transistor per relay in the system then. With a transistor, will I still need the diodes?
The other concern I have is the voltage requirement. The datasheet on the PT2272 says 4-15 Volts. I assume since this receiver is advertised as 5v there is something else limiting the voltage. I would like to power the motors and the receiver with a 4xAA battery pack (4x1.5v = 6v nom.). Would this cause any problems, or do I need to drop the voltage first?
The other concern I have is the voltage requirement. The datasheet on the PT2272 says 4-15 Volts. I assume since this receiver is advertised as 5v there is something else limiting the voltage. I would like to power the motors and the receiver with a 4xAA battery pack (4x1.5v = 6v nom.). Would this cause any problems, or do I need to drop the voltage first?
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Re: Simple RF M4 Receiver connection question
A small transistor such as a PN2222 should do the job: http://www.adafruit.com/products/756
You still need the diode to protect the transistor: http://www.adafruit.com/products/755
You still need the diode to protect the transistor: http://www.adafruit.com/products/755
The chip itself is rated for 4-15v. The complete receiver module is rated for 5-10v. A 4xAA battery pack will work fine.The datasheet on the PT2272 says 4-15 Volts. I assume since this receiver is advertised as 5v there is something else limiting the voltage.
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Re: Simple RF M4 Receiver connection question
Your diodes should be in parallel with the coils as in the diagram here: http://makezine.com/2009/02/02/connecti ... o-arduino/
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Re: Simple RF M4 Receiver connection question
Looks like you are also missing the base resistors. For a 2n2222, 1Kohm should work.
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Re: Simple RF M4 Receiver connection question
That looks better!
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Re: Simple RF M4 Receiver connection question
very cool. I'll run with it then. Thank you for the help on this
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Re: Simple RF M4 Receiver connection question
May I ask why you grounded VT? Documentation shows this as an output driving a LED to show receiver activity.
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Re: Simple RF M4 Receiver connection question
Good catch. That output should be left open - or you can connect an indicator led if desired.May I ask why you grounded VT? Documentation shows this as an output driving a LED to show receiver activity.
Please be positive and constructive with your questions and comments.