Hi all,
I'm building a medium power h bridge motor controller. It's based on the controller here . I'm using similar, but higher rated, components. And of course, I'll be heatsinking the transistors.
My motor's stall current is around 8 amps, and average current is around 1.5 amps. It's running on at least 24 volts, which I might step up to no higher than 50 volts.
I have these nifty project PCBs that have traces imitating a breadboard (see photo of red board below). Right now I'm using it for the low-power, digital interface. Sites like this seem to suggest that I'd be loony to try to use the board, with 1 oz copper, to control the transistors that have to provide up to 8 amps. Note: I'd like my circuit to be able to handle the stall current continously, just in case the motor gets stuck when left unmonitored. Additionally, the wiring standards seem to indicate that I need some pretty beefy lines for 8 amps continous. Icker than 18 gauge, apparently.
So I've used some perf board to hold it all together (see yellow board below). the problem is that the circuit requires a great number of connections be made to the transistors. So in very close quarters, I have to solder several thick wires, pull down resistors, a signal line, and a protective diode. This gets to look pretty ugly on perfboard.
I have two questions:
1: Does anyone have any tricks for dealing with connecting several large components on perf? Stacking the connections sort of worked, but it looks ugly, requires applying heat to the transistor terminal for a long time, and seems like a risk for shorts.
2: It seems like the ratings all demand super thick traces and wires for this kind of power, yet the wire I'm supposed to need is many times the thickness of the transistor legs. How could it be that, to be safe, my wire needs to be that much thicker than the transistor leg sourcing/sinking the current? I've also seen many prebuilt high power motor controllers with traces no thicker than those on my project PCB. Is there any reason they can handle this current while my PCB, supposedly, can't?
I'm building a medium power h bridge motor controller. It's based on the controller here . I'm using similar, but higher rated, components. And of course, I'll be heatsinking the transistors.
My motor's stall current is around 8 amps, and average current is around 1.5 amps. It's running on at least 24 volts, which I might step up to no higher than 50 volts.
I have these nifty project PCBs that have traces imitating a breadboard (see photo of red board below). Right now I'm using it for the low-power, digital interface. Sites like this seem to suggest that I'd be loony to try to use the board, with 1 oz copper, to control the transistors that have to provide up to 8 amps. Note: I'd like my circuit to be able to handle the stall current continously, just in case the motor gets stuck when left unmonitored. Additionally, the wiring standards seem to indicate that I need some pretty beefy lines for 8 amps continous. Icker than 18 gauge, apparently.
So I've used some perf board to hold it all together (see yellow board below). the problem is that the circuit requires a great number of connections be made to the transistors. So in very close quarters, I have to solder several thick wires, pull down resistors, a signal line, and a protective diode. This gets to look pretty ugly on perfboard.
I have two questions:
1: Does anyone have any tricks for dealing with connecting several large components on perf? Stacking the connections sort of worked, but it looks ugly, requires applying heat to the transistor terminal for a long time, and seems like a risk for shorts.
2: It seems like the ratings all demand super thick traces and wires for this kind of power, yet the wire I'm supposed to need is many times the thickness of the transistor legs. How could it be that, to be safe, my wire needs to be that much thicker than the transistor leg sourcing/sinking the current? I've also seen many prebuilt high power motor controllers with traces no thicker than those on my project PCB. Is there any reason they can handle this current while my PCB, supposedly, can't?