elsey.jack
New Member
Hello everyone,
I'm working on a weather balloon for a research project. It will be moored to the ground and reach a height of 100 meters. There will be two modules. One module will be attached to the balloon and will transmit the temperature (via a 434 Hz RF transmitter) to a hand held module where it will be displayed.
The range of the RF transmitter is dependent on the voltage supplied to it. A maximum of 500 ft through open space is achievable with 12 V as a supply voltage. The PICAXE 18X microcontrollers that I am using to control the modules runs off of a 4.5-5.5 supply voltage.
The prototype that I have built of the balloon module uses about 25-30 mA with the RF transmitter at 5V.
I need a lightweight battery that will power the balloon module for about 1-1.5 hours. I was looking at lithium polymer batteries but each one of those only gives me only 3.7 volts.
I could buy more than one lithium polymer battery and link them in series to get a higher voltage, but I would have to get smaller batteries with a shorter battery life.
Could I possibly use a transformer to boost the voltage from a 3.7 V battery to 12 V? Can transformers only be used with AC voltages? Do they make transformers light enough for my purposes?
Thanks,
Jack
I'm working on a weather balloon for a research project. It will be moored to the ground and reach a height of 100 meters. There will be two modules. One module will be attached to the balloon and will transmit the temperature (via a 434 Hz RF transmitter) to a hand held module where it will be displayed.
The range of the RF transmitter is dependent on the voltage supplied to it. A maximum of 500 ft through open space is achievable with 12 V as a supply voltage. The PICAXE 18X microcontrollers that I am using to control the modules runs off of a 4.5-5.5 supply voltage.
The prototype that I have built of the balloon module uses about 25-30 mA with the RF transmitter at 5V.
I need a lightweight battery that will power the balloon module for about 1-1.5 hours. I was looking at lithium polymer batteries but each one of those only gives me only 3.7 volts.
I could buy more than one lithium polymer battery and link them in series to get a higher voltage, but I would have to get smaller batteries with a shorter battery life.
Could I possibly use a transformer to boost the voltage from a 3.7 V battery to 12 V? Can transformers only be used with AC voltages? Do they make transformers light enough for my purposes?
Thanks,
Jack
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