Relays

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Adam Hargreaves
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Relays

Post by Adam Hargreaves »

My reciever uses 4.8V, but, as I'm having battery pack problems, could it work using 4.5V?
Last edited by Adam Hargreaves on Wed Aug 24, 2005 8:01 pm, edited 1 time in total.
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josh
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Post by josh »

it should work i geuss my receiver is a 4.8 and has been known to work on 3.5 :wink:
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Post by Adam Hargreaves »

yay :D
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BeligerAnt
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Post by BeligerAnt »

Remember 4.8V is only the nominal battery pack voltage (4 x 1.2V). A NiCd or NiMH cell is considered "flat" when it gets to about 1V. Similarly when first charged the cell voltage can be as high as 1.6V.
This gives from 4.0V to 5.6V for a 4-cell pack under normal operating conditions.
A well-designed receiver *should* work comfortably down to 4.0V, however, experience shows that at least some receivers start to behave erratically when the battery voltage drops.
One important thing to consider is the voltage that your 4.5V pack will drop to as it discharges. If you are using 3 x 1.5V alkaline cells, the voltage will drop fairly steadily towards about 1V (per cell). They are usually considered "flat" around 0.8-0.9V per cell.
Unfortunately, receiver operating voltage ranges are not usually clearly given (if at all!), but I would expect a receiver to work down to maybe 3V if it has a "clean" supply. If you drive the motors from the same batteries, you are likely to experience problems at higher voltages.
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Post by american roboteer »

like the ant i just built works fine but when the disk is running it gets sluggish and less responsive i just learn to live with it i guess :(
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BeligerAnt
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Post by BeligerAnt »

You can try a few things to improve your situation...
1) Move the receiver (and antenna) as far away as possible from the motor. Keep the motor wiring away from the receiver and antenna.
2) Add a small ceramic capacitor across the motor terminals.
3) Try connecting a small capacitor from each motor terminal to 0V.
4) Try connecting a wire from the metal body of the motor via a capacitor to 0V.

Hope that helps.
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Adam Hargreaves
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Post by Adam Hargreaves »

My reciever will survive on 6 Volts (yay). New question, if I make my own pack with NiCD ir NiMH AAA batteries, can I charge them with my Rx charger, or will I need to dismantle the pack and charge using a 'normal' charger?
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Post by american roboteer »

worked for me i charged mine from the charger my tx came with it didnt explode :D
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Post by Andrew_Hibberd »

The RX port on the standard charger gives about 6V so won't charge a 6V battery very well. The Tx port gives about 10V so can be used to charge a 6V pack. Remember to test which is positive the inner or outer part. Also don't charge for more than 5 hours (a 70mah charger with a 300mah battery) Hopes that helps a little bit
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Post by Adam Hargreaves »

well it'll be 4*1.2 Volt cells, so it'll be 4.8V. The 6 Volts were from normal alkaline ones (which i know cannot be recharged before anybody says anything)
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