Hi! I've a noob question
Hi! If my H-bridge is rated 15A and I want to use a stepdown voltage regulator for my motor. Do I also need around 15A voltage regulator so the H-bridge can output 15A?
Hi! I've a noob question
Hi! If my H-bridge is rated 15A and I want to use a stepdown voltage regulator for my motor. Do I also need around 15A voltage regulator so the H-bridge can output 15A?
Your regulator should be capable of providing more than 15 amps.
Tamulmol:
Hi! If my H-bridge is rated 15A and I want to use a stepdown voltage regulator for my motor. Do I also need around 15A voltage regulator so the H-bridge can output 15A?
Yes, if you really need the H-bridge to output 15A. What is the stall current of the motor?
A motor H-bridge would typically be driven from an unregulated supply (e.g. a battery) or from a switching power supply.
I think it's 6.6 stall current and 6v Motor. I'm planning to use lipo battery but the closest voltage is 2s 8.4v at full charge.
I can't find more than 10A stepdown voltage regulator that I can solder on board(the Mosfet looking regulator LOL). Is it ok to directly connect battery to h-bridge? unregulated supply to motor? Thanks!
Tamulmol:
I think it's 6.6 stall current and 6v Motor. I'm planning to use lipo battery but the closest voltage is 2s 8.4v at full charge.I can't find more than 10A stepdown voltage regulator that I can solder on board(the Mosfet looking regulator LOL). Is it ok to directly connect battery to h-bridge? unregulated supply to motor? Thanks!
It's OK to use an unregulated supply. First, from the datasheet of the H-bridge, work out the voltage drop @ 6.6A. Subtract that from the 8.4V to see what the remaining voltage is. If it is more than 6V, then the simplest solution is to limit the maximum PWM value according to the battery voltage. Alternatively, you could use a 8A or 10A silicon diode to reduce the voltage (and also provide protection against connecting the battery the wrong way round). a silicon rectifier diode drops typically 1V at its rated current, but check the datasheet because some have a higher voltage drop.
Add a fuse at the battery - LiPo's output extreme currents if accidentally shorted.
8.4V is not so much more than 6V (and that's full charge without load voltage), if you use PWM you need
not take it all the way to 100% if you don't need to...
Tamulmol:
Hi! I've a noob questionHi! If my H-bridge is rated 15A and I want to use a stepdown voltage regulator for my motor. Do I also need around 15A voltage regulator so the H-bridge can output 15A?
While the rated max current for the H-bridge may be 15A, the actual maximum current draw depends on the specific electrical voltage/current specifications of the motor itself. Your voltage source need be rated no higher then the actual maximum motor current requirement. So if the motor can only draw say 5 amps maximum, then your power supply need only rated for 5 or more maximum amps.
One advantage of using a voltage regulator chip is that most of then have automatic over current protection such that the chip just folds back (lowers) it's output voltage to cause the current flow to be safely limited without damage to the chip. Using a unregulated DC voltage source requires you to fuse the voltage source to prevent possible damage.
Lefty
Thanks for the replies! Im gonna limit PWM and add a Fuse, I once melted my aligator clip, I accidentally shorted lipo. What voltage regulator chip do you guys use for more than 10A? I still wanna learn to make one