Many Motors simultaneously through Shift register 74HC595

Hello there,

im trying to control some motors/ other power consumers simultaneously. Currently i'm using the 74HC595 Shift Register in paralell-out mode connected to several mosfets connected to a higher power supply. My question is if the shift register can handle up to 5 devices at the same time or if the the power supply would be devided by 5 so all devices/ motors would run at speed/5? The power consumers vary from 150mA to like 600mA all with 12v.

Or maybe is there a better way to achieve the same effect with a different IC? Im trying to use as less outputs on my arduino as possible, because i'll need them for other components witch will be added later.

Datasheet Shift Register
Datasheet Mosfet

Thanks for helping me out.

OPs image

the 12v power rails on the bottom breadboard should be connected as well. Forgot those.

What is "a higher power supply."? What are your loads?
The MOSFETs are not connected correctly, page 9 on datasheet, should be like the first drawing HERE:

My question is if the shift register can handle up to 5 devices at the same time or if the the power supply would be devided by 5 so all devices/ motors would run at speed/5?

No, each load will get the full power supply voltage as long as the PS can supply enough CURRENT for all loads.

a higher power supply

its 12v, 3A power supply

What are your loads

it can vary from about 12v/800mA to up to 12v/2.6 depending if the "task" is more complex.

The MOSFETs are not connected correctly

You're correct.

So the question for me is if the shift register will have enough power to drive 2-5 paralell outs with full load or if the load is splitted amongst all devices therefore they will run at lower speed/ etc

See my edit, remember, motors will draw much higher current when first starting, so try not to start them at the same time. The SR is only handling signals, it's the PS and MOSFETs that handle the load current.

ahh didnt see that ...
thank you sir.

To be honest it kind of feels bad to use 4 shift register to power 20 mosfets for All of my devices. the problem is that about 10 have to be controlled in different speed (analog Signal through mosfets) the others on Füll Power through mosfets with pulldown resistors.
Would it be better to use power shift registers or mosfet-arrays to do it the more elegant way?

The best way i could come up so far is use a combination of several ULN2003 and regular IRLZ34N-Mosfets

Are all of your devices 800mA motors?

no. only 2 motors wich need to 700mA peak. The rest vary from 150mA to 400mA.
But some of them run a full power some need to be adjusted through pwm

If you want to use PWM, a shift register is a poor choice, you'd need some pretty tight coding to drive multiple PWM signals through a shift register. There are multi-channel PWM chips and modules that can do the task better. For instance Adafruit 16-Channel 12-bit PWM/Servo Driver - I2C interface [PCA9685] : ID 815 : $14.95 : Adafruit Industries, Unique & fun DIY electronics and kits

Remember those free-wheel diodes with inductive loads. If that doesn't make sense google about driving motors and relays with a MOSFET.

For instance Adafruit 16-Channel 12-bit PWM/Servo Driver - I2C interface [PCA9685] : ID 815 : $14.95 : Adafruit Industries, Unique & fun DIY electronics and kits

That would be great, but can only handle up to 6v, sadly i need 12v.
Could I run it together with the mentioned ULN2003? I can't read out of the datasheet if this chip can handle analog signals or just digital.

smaresh:
That would be great, but can only handle up to 6v, sadly i need 12v.

Your MOSFETs need to handle 12V on the output, they can be driven from 5V if logic-level.

Your MOSFETs need to handle 12V on the output, they can be driven from 5V if logic-level.

thats true, but

To be honest it kind of feels bad to use ... to power 20 mosfets for All of my devices

with the uln2003 I would only need 4 ics and extend my current shift registers. With the stepper driver module I would control them with i2c to 20 mosfets. Thats way more space on a pcb and way more expensive. Or I did get something wrong?

Most of theese 20 devices only need to run at full speed in 1 direction. I got an other stepper motor in my project, which is run by LM293D.

Have you looked at the ST L9733, it has MOSFET outputs and 8 per chip, rated at Max 800mA per output. Here are many of the nice deatures of the chip you may like:
 AEC-Q100 (Rev. F) qualified
 Eight independently self configuring low/high drivers
 Supply voltage from 4.5 V to 5.5 V
 RON(max) = 0.7 Ω @ Tj = 25 °C, RON(max) = 1.2 Ω @Tj = 125 °C
 Minimum current limit of each output 1 A
 Output voltage clamping min. 40 V in low-side configuration
 Output voltage clamping max. -14 V in high-side configuration
 SPI interface for outputs control and for diagnosis data communication
 Additional PWM inputs for 3 outputs
 Independent thermal shutdown for all outputs open load, short to GND, short to Vb, overcurrent diagnostics in latched or unlatched mode for each channel
 Internal charge pump without need of external capacitor This response is to help you get started in solving your problem, not solve it for you.
Good Luck & Have Fun!
Gil

Maybe there could be a single set PWM signal being generated and this signal be controlled to various devices by a latching multiplex chip.

Thank you, that looks like a very interresting ic.