H-Bridges of Madison County: 77 Cents
https://www.ebay.com/itm/1-5A-Mini-Dual-Channel-DC-Motor-Driver-Module-Beyond-L298N-PWM-Speed-control-ESC/232732824698
I'll be forced to unfriend anyone who doesn't order at least ten units.
Oh sorry, wrong social media.
I'll just keep on Tweeting until everyone confirms buying ten.
Oops. My bad. Snapchatters, snap off a few of these...
What? Wrong forum again? DOH!
I've been impressed using these MX1508s in some prototypes lately. I've stalled toy grade motors on 5V and they don't mind at all. Heck, you can barely buy a single decent MOSFET for 77 cents. These can coast or brake, BTW.
Fake Chinese specs, use at your own risk, but I wouldn't push it:
Supply voltage 2V ~ 10V, can drive two DC motors or a 4-wire 2-phase stepper motors ,can achieve forward rotation or reverse rotation, it is possible to adjust the rotation speed. Each can provide continuous current of 1.5A, peak current up to 2.5A
I'll be forced to unfriend anyone who doesn't order at least ten units.
Oh sorry, wrong social media.
I'll just keep on Tweeting until everyone confirms buying ten.
Oops. My bad. Snapchatters, snap off a few of these...
What? Wrong forum again? DOH!
I've been impressed using these MX1508s in some prototypes lately. I've stalled toy grade motors on 5V and they don't mind at all. Heck, you can barely buy a single decent MOSFET for 77 cents. These can coast or brake, BTW.
Fake Chinese specs, use at your own risk, but I wouldn't push it:
Supply voltage 2V ~ 10V, can drive two DC motors or a 4-wire 2-phase stepper motors ,can achieve forward rotation or reverse rotation, it is possible to adjust the rotation speed. Each can provide continuous current of 1.5A, peak current up to 2.5A
1500 x 1011 - 255K
Comments
http://www.instructables.com/id/Tutorial-for-Dual-Channel-DC-Motor-Driver-Board-PW/
From http://www.robotop.lv/en/aksessuary-drajvery/500-mx1508-2-channel-dc-motor-driving.html :
Products introduction: motor drive module very for in battery power of intelligent car, and toy car, and robot, above using, power voltage 2V~10V, can while drive two a DC motor or one 4 line 2 phase type step into motor, can achieved pros and cons turned and adjustable speed of function, each road current can to 1.5A continued current, peak current can up 2.5A, has hot protection and can automatically recovery.
Between to and fro PLUS pros and cons, this baby does it all!
I will admit not to buying 10. For my use 10 would be hording, and hording is a bad habit. My old 5 bedroom, 2 1/2 car garage house was a testament to that.
I got four, which is several more than I'm likely to use. Sadly, I can't write about them in published work because likely they'll be gone or altered for any kind of decent shelf-life for a book or even article -- 'tis the nature of eBay. Gotta relegate them to my personal stash. That said, it's nice to get an H-Trestle for a buck.
A Canadian buck, that is! Worth smoke testing at that price. This Russian fellow appears to like them too. At the end of his video, he "hot wires" the H-bridge with a single wire to B+, demonstrating that the input pins have integral pulldown resistors.
That said, it's nice to get an H-Trestle for a buck.
LOL
Jim
It cracks me up sometimes the way they translate things such as datasheets.
On the other hand, apparently DMV translations were done using Google.
You've posted that before, it's funny.
Did you ever see the EEVBlog episode where Dave was mailed a Cen-Tech multimeter?
He makes fun of the safety rules.
"Don't work alone...................I'm screwed!"
"You have to wear the proper safety equipment when using a multimeter."
from specs at https://www.sparkfun.com/datasheets/Robotics/L298_H_Bridge.pdf
OPERATING SUPPLY VOLTAGE UP TO 46 V
TOTAL DC CURRENT UP TO 4 A
-Phil
Yup. You definitely don't want "very burn" in your high-reli application.
Expect to see it at Maker Faire San Mateo this month!
Adding two diodes per H-bridge on the L298N lets you select coast or brake without using a third micro connection to the ENable pin. Truth table attached. The stock L298 module comes with two removable jumpers which connect both ENable pins to +5V, which turns dynamic braking on all the time. Even during the OFF periods of PWM. That's pure madness, causing unnecessary mechanical wear & tear on the gearmotor.
BTW, according to https://www.bananarobotics.com/shop/How-to-use-the-L298N-Dual-H-Bridge-Motor-Driver , the L298N's built-in 5V regulator is only good for input voltages up to 16V. Glad I caught that and removed the default jumper before connecting to 28V for the smoke test.
https://www.mouser.com/ProductDetail/ON-Semiconductor/LV8548MC-AH?qs=sGAEpiMZZMuleuVm2ofeX1ZeyMQNcmgu
Runner-up at 87cents but with current sense and internal pwm.:
https://www.mouser.com/Search/Refine.aspx?Keyword=MTS62C19A-HS105
MX1508 can be had for 21cent/each for 100units shipped free from China:
https://www.aliexpress.com/item/Free-Shipping-100pcs-lots-MX1508-SOP-16-IC-In-stock/32857760816.html
I'm thinking you always need to PWM the line that's HIGH, which means your MCU has to have four pins with PWM instead of just two (if you want speed control for reverse and turns). On some controllers that's not a problem, but on an Arduino there are only some pins with PWM, and they're connected to specific internal hardware timers. You'd use two (of the three in an Uno) just for this.
Such is not a problem in Propland, and I think any PICAXE M2 part will have no trouble.
You miss nothing, Master Roboto!
I'm not normally a fan of L298s since they drop several volts. That's quite noticeable in a 6V system. But when using these 24VDC system, what's a few volts between friends? They're rated to ~35V, and at the low currents these gearmotors draw, that heatsink shouldn't heat up much.
Theoretically.
Ah, so... I see what you mean. If you have more dollars than sense regular lines than PWM lines, then apply PWM only to the enable pin, and set the direction on the IN pins using non-PWM pins.
Barely related: besides PWM, my current project uses two eBay relay modules. Control signal is active LOW, who knew? I'm really glad they silkscreened screw images by the holes so I know what's supposed to go through there. I just couldn't figure that out.
So I'm going to be doing some eBay buying this weekend. I'm going to pick up a few more of these Madison County bridges, plus try to find the Wowwee/Dagu motors with the thinner wheels--the kind Feetech uses on their little circular bot. Have you seen those sold separately on eBay? I found some Feetech converted servos (DC interface) and matching wheels on Amazon, but not yet on eBay.
I'm also looking for a good source for a buck boost regulator, similar to the bucking stepdown you had noted earlier (and which I got already).
Finally, any good handle on some cheapo standard (size and non-CR) servos -- the 995s might be good, but I hear the really cheap imports have lousy deadband and aren't at all accurate. I need about 10 to basically ruin, and I ain't doin' that with my Parallax Futaba servos.
https://www.ebay.com/itm/5V-1-Channel-Relay-Board-Module-Optocoupler-LED-For-Arduino-PIC-ARM-AVR-HF/382438731142
Not sure if I left any H-bridges for you to buy... my ten-pack arrived today! I'll actually use most of these on a new project.
Will look into those wheels. I bought some long ago, can't recall where.
I've stopped using those 995 servos, they overheat & burn up. I gut them and use them as gearmotors, without electronics. They have gotten worse since they were called the world's worst servo. http://www.rcmodelreviews.com/mg995review.shtml
Gotta be better than a certain "Arduino compatible" buzzer I had to use for a project I wrote about. The thing was active LOW, and it it started buzzing before the Arduino could go through its startup routines. Since it was meant to directly plug into the Arduino (no room for a pull-up resistor), it was extraordinarily annoying.
First video on my new dedicated tech channel, Nytrobotics!
Do they really not know? https://www.walmart.com/ip/Unique-Bargains-40mm-Diameter-Internal-Magnetic-Type-Speaker-4-Ohm-3W-for-Toys/187540094