Hey guys, I looked over the manual for the BBII and didnt see what it could take as an input voltage. I did see in the SSC32 manual that it can take 6vdc-9vdc, is the BBII the same specs?
I am planning on upgrading to LiPo and wondering if I can use the same regulator that I am using for the servos, or if I should just directly connect the 7.2vdc lipo to the BBII and SSC32?
And as a side note… I have started seeing a lot of stuff on LiFePo4 batteries… is anyone using them yet? is it worth upgrading my charger to one that supports lifepo and getting a lifepo battery? Or should I just stick with LiPo right now since I already have a charger?
The VL circuitry is the same for the two boards. We implemented a LDO regulator so you need at least 6vdc coming in to get 5vdc out. voltages up to 9.6 will be fine. The regulator is spec’d at 500mA but we are mounting it vertical to save space so there is no heat sink. We de-rated the spec to 250mA so the regulator will not heat up.
The higher the input voltage the more work the regulator needs to do to provide the 5vdc out. If the input voltage is 6vdc then the regulator drops 1vdc. If the input voltage is 12vdc the regulator drops 7vdc. Ok so 1 volt, 7 volts so what… Well lets do some math.
voltage X current = power
1 x .250 = .250 watts <- a quarter of a watt is nothing. The regulator will not heat up.
7 x .250 = 1.75 watts <- the regulator can get warm.
7 x .500 = 3.50 watts <- without a heat sink… hot.
That makes sense…
My only question is, where are you pulling the current values from? Just associating the numbers from the first paragraph, they are the mA values?
so if I had a 6000 mAh 7.2v battery, that would be
2.2 x 6 = 13.2 watts? Obviously WAY too much…
I have read some people using the Turnigy regulator, but I can only seem to find them sold at One hoby shop
I listed .250 so that’s in amps. 0.250 amps is the same thing as 250mA.
In your example you are listing the battery capacity, or it’s ability to deliver current. I was listing examples of how much current could be drawn from the on board regulator. The two terms couldn’t be more different. There is no way the 500mA regulator could deliver 6 amps. It would go into thermal shutdown and (hopefully) not self destruct.
