How to make a high amp ESC

[calvino]

I am currious if anyone has plans for an ESC that can drive a bit of amps (like maybe 20+ stalled), that can suply a motor 12 volts, it is for a robot idea i have, also, any way to make it work with standard radio equipment, thanks :)

[AndyKunz]

There are lots of designs on the web. Do you want it to run in both directions (reversing) or just one?

BTW, 20A is nothing. I will soon be releasing my Victory ESC to the public domain, a 90A programmable control.

Andy

[calvino]

There are lots of designs on the web. Do you want it to run in both directions (reversing) or just one?

BTW, 20A is nothing. I will soon be releasing my Victory ESC to the public domain, a 90A programmable control.

Andy
um, it is to be for a ground based bot idea/RC car, so, yeah, reverse sounds good, I found a few plans but, they didn't seem to look like they would work with a standard radio system, 20 was like a guess, heck, higher amp suply it can do the better :) , found a few links, should get them up, but, they didin't seem to totally fit the application :eek: :mad:

[AndyKunz]

I guess I'm surprised that you found ones that weren't for standard radios. What were they for?

Andy

[calvino]

I guess I'm surprised that you found ones that weren't for standard radios. What were they for?

Andy
more for running off of microcontrollers which decoded the radio signal, my thingie is, I don't want to spend $100+ on a PIC programing software pkg to program a $2.00 Microcontroller, it does't make any sense, I found some, but most are for planes and all they have is brake and that is all, I have this circuit, but, how would I couple it from like a servo amp was my problem :confused:

[funfly2]

I guess you just have to connect the output from an existing servo amplifier to the input of this circuit (forward & reverse controls).
;)

[calvino]

I guess you just have to connect the output from an existing servo amplifier to the input of this circuit (forward & reverse controls).
;)
I guess so, now all I have to do is design a PCB :rolleyes:

[AndyKunz]

That schematic is just the "hot section." Like you said, you need something to drive it. That's not rocket science at all. Lots of folks will burn them for you gratis. If you select a PIC and e-mail me the hex file, I'll be happy to burn it for you. Depending upon what you select, I may already have one sitting here and would be happy to just burn and ship.

Having a PIC in there makes your whole unit simpler, more reliable, and easier to upgrade. There are several free designs out there for PIC-based reversing ESCs. Select one and I'll be happy to get it burned and out to you.

Andy

[calvino]

That schematic is just the "hot section." Like you said, you need something to drive it. That's not rocket science at all. Lots of folks will burn them for you gratis. If you select a PIC and e-mail me the hex file, I'll be happy to burn it for you. Depending upon what you select, I may already have one sitting here and would be happy to just burn and ship.

Having a PIC in there makes your whole unit simpler, more reliable, and easier to upgrade. There are several free designs out there for PIC-based reversing ESCs. Select one and I'll be happy to get it burned and out to you.

Andy
ok, yeah, the thing is, i think it is the compilier that they burn you on, as for the other stuff I have no clue, I do know that there are some ESC's that DON"T use PIC's but, they don't work so good, I do have a program (lying in a book somewhere) that has a decoder program for a PIC I believe, just currious what it does take to "burn a pic" :). OK a little Google hunting turned up this cool plan, http://www.mcmanis.com/chuck/Robotics/projects/servo.html the neat thing is, the dude who wrote the program says he can ship you a "burned pic" for $5.00, got some other plans I am checking out. here is even more on it, http://www.mcmanis.com/chuck/Robotics/projects/h-bridge/h-bridge.html this one looks like "the one". the dude who wrote it say it can handle 20A no heatsinks on Mosfets, and pushing 40A with sinks on the Mosfets, so, :)

[AndyKunz]

So there's your solution. $5 for the PIC, programmed, and you got what you need.

You don't need a compiler, but you can download free ones from several sites (Microchip, HTSoft.com, etc.) and the burners you can make from spare parts in your junk bin if you do a little googling.

One thing you'll find around here is that an awful lot of guys are willing to help with details like getting you a burned chip, but you're gonna have to do a little legwork to find the design you want to build.

Andy

[calvino]

So there's your solution. $5 for the PIC, programmed, and you got what you need.

You don't need a compiler, but you can download free ones from several sites (Microchip, HTSoft.com, etc.) and the burners you can make from spare parts in your junk bin if you do a little googling.

One thing you'll find around here is that an awful lot of guys are willing to help with details like getting you a burned chip, but you're gonna have to do a little legwork to find the design you want to build.

Andy
yeah, but if i needed something "now" or it was a defective chip..... just currious, since the chips are cheap.... ok, what about software, can that be found cheap......... :) , I am kindof a cheap guy as you can prob tell :D

[AndyKunz]

Google for "David Tait Programmer" - it's dirt cheap to build and runs with free software.

Free compilers are available from www.htsoft.com (select "Downloads" on pull-down menu).

IDE and compilers are available from www.microchip.com - look under development tools, MPLAB, etc.

Andy

[calvino]

Google for "David Tait Programmer" - it's dirt cheap to build and runs with free software.

Free compilers are available from www.htsoft.com (select "Downloads" on pull-down menu).

IDE and compilers are available from www.microchip.com - look under development tools, MPLAB, etc.

Andy
thanks alot andy, should look em up :) , sounds cool, now all I have to do is design a PCB....

[AndyKunz]

You can download PCB Gerbers for free too...

Andy

[calvino]

You can download PCB Gerbers for free too...

Andy
ok, I gues all the "answers" are in google :p , should get around to doin that sortof stuff, thanks for the help....links... man, you guys are SOOOOO nice.... :cool:

[mjsas]

If you go to EBAY and search for outrunner in the toys and hobby section there will be numerous motors and ESC's at a price lower then you can build them. I got an 80 amp ESC for under $30. If you look, there are BLDC ESC's rated at over 400 amps, 20 amp is small stuff.
All the manufactures of microprocessors (TI, Atmel, etc.) have application notes describing how to design brushless motor controllers. Most include the software. Note that these designs usually are not suitable for aircraft use. For aircraft use it is desired to have 1/2 power when the throttle is set at 1/2 with no regard to RPM, just like with a gas engine. With a gas engine 1/2 throttle gives, well, 1/2 throttle. This is the simplest control algorithm, but most other applications require RPM control instead of power control. Controlling RPM can get very complicated.

You can use the simple trapezoidal control everyone knows and loves or a more complex algorithm such as field oriented control which gives more power.

It was mentioned that only PIC based ESC's are any good, that is a crock. You can build a good ESC using micros from any manufacture.

[calvino]

If you go to EBAY and search for outrunner in the toys and hobby section there will be numerous motors and ESC's at a price lower then you can build them. I got an 80 amp ESC for under $30. If you look, there are BLDC ESC's rated at over 400 amps, 20 amp is small stuff.
All the manufactures of microprocessors (TI, Atmel, etc.) have application notes describing how to design brushless motor controllers. Most include the software. Note that these designs usually are not suitable for aircraft use. For aircraft use it is desired to have 1/2 power when the throttle is set at 1/2 with no regard to RPM, just like with a gas engine. With a gas engine 1/2 throttle gives, well, 1/2 throttle. This is the simplest control algorithm, but most other applications require RPM control instead of power control. Controlling RPM can get very complicated.

You can use the simple trapezoidal control everyone knows and loves or a more complex algorithm such as field oriented control which gives more power.

It was mentioned that only PIC based ESC's are any good, that is a crock. You can build a good ESC using micros from any manufacture.
yeah, but the PIC Is cheap and most of the software is designed for them, the thing for me is, the motors (Makida Cordless Drills), draw AMAZING amounts of power at startup, so, my thing was, why not make an insane offroad platform that uses these powerhouses (more like RPM machines), the last thing I want to do is use like a $50+ Basic Stamp ESC to operate a single motor, when a $4.00 MC can do the same :confused: