Hello to you all,
I also have the ta8435h, but I cannot figure out how to connect the power supply to the board, the connector has 4 pins, but I only have two wires from the supply, could someone tell me?.. where they go
12 v , 2 a
just two wires 1st plus, second ground
The TA8435H chip uses the voltage drop in those resistors to feed a comparator that chops the current. The comparator has a multiplexer that switches between 0.8V and 0.5V. I beleave that the 0.8V is used when pulses are present in the parallel port, and 0.5V in idle (how long it takes to switch to idle is still a mistery, they just say it uses a 555 chip, as monostable I would gess, but time constant is not at all documented).
That means that, using 0.5 ohm resistors you will have:
- 1.6 Amp when moving
- 1.0 Amp when idle.
The 1.6 Amp looks a bit of a stress as the chip is rated 1.5 Amp RMS max. But using 1/2 step or less, each phase should get in average less than 1.5 Amp. So I would avoid full-step mode with that board.
can anyone help, I have the ta8435h board connected to three stepper motors fl57sth76-2808b 8wire, controlled by mach 3. when connected all the led's remain lit, the motors will not turn by hand, but nor will they move from the keyboard. the power supply comes from a 19v/ 4.74a supply. there were no instructions on how to configure the ports and pins in mach3, can anyone help or suggest a site were I could find this infomation.
I thank you for taking the trouble, but for some reason I cannot access this site. I have tried different variations with no luck, any suggestions would be
I have just logged in to the site
By the way there is some inconsistency over PS max volts in the board manual. Some places state 36V other places say 24V. I would anyway not try anything above 24V. I have seen reports of people setting the TA8435 on fire when going just above 30V. The datasheet of the TA8435H chip states 26.4V as the maximum recommended.