12v --> 10v Nowforever D100S2R2B inverter & MKS-V-V02 CDXHCTECH board

[EddyCurrent]

Maybe you could adjust these parameters, specifically "P0-024 max input corresponding frequency"

But before changing anything, what are they set to now ?

P0-021 AIN min input Setting range 0.00～10.00V
Factory value：0.00V
P0-022 AIN min input corresponding frequency Setting range 0.00～600.00Hz
Factory value：0.00Hz
P0-023 AIN max input Setting range 0.00～10.00V
Factory value：10.00V
P0-024 AIN max input corresponding frequency Setting range：0.00～600.00Hz
Factory value：50.00Hz

[routercnc]

One for the electronic experts - would a pair of resistors in series across the 12V output with values chosen to give 10V at the centre tap point work? All outputs would be 10/12 ths of the input so it would track all intermediate speeds ? If so just 2 cheap components required

[magicniner]

One for the electronic experts - would a pair of resistors in series across the 12V output with values chosen to give 10V at the centre tap point work? All outputs would be 10/12 ths of the input so it would track all intermediate speeds ? If so just 2 cheap components required

That's a classic Voltage Divider and Yes, it will work provided your circuit can carry enough current to deliver the signal current required (V=IR)
Do the maths in combination with the input impedance data from the controller manual.
Remember that sourcing any current from a simple resistor based Voltage Divider will skew the output, you need to know the input impedance and available current to work out the values which will safely give the best result.
Hence my suggestion of an Op Amp circuit with fractional gain.

- Nick

[Doddy]

Okay, had a quick look at the data sheets for both the inverter and the controller. OP is quite correct - the controller expects to be supplied a 10V supply from (e.g.) inverter, and will presumably generate a 0-Vref for the spindle speed. What is needed is to reduce the 12V reference voltage to 10V. A simple way to do this would be to place 3 silicon diodes in series with the 12V output from the spindle.

+12 -------->|------>|------>|------------- +10V In

Diodes 1N4001, or similar would be good enough and cost pennies each.

You could put a LM317 regulator inline - with 2V difference between Vin and Vout, it should manage well enough, but it's probably a sledgehammer to crack a nut.

There is also a AO1 analogue output on the inverter, range 0-10V, but I can't figure out a way to use this to generate a constant 10V output.

[Neale]

I would go for the diode solution as well. Even if you buy from Maplin, they're still cheap enough and it's a better solution than resistors. Tweak the calibration as also suggested here (if needed - give or take a few per cent, spindle speed isn't that important) and job's done.

[magicniner]

A fixed 2 Volt drop may be acceptable for the OP's requirements and that's an elegant solution if such is the case, I had Tunnel Vision on an output proportional to the input,

- Nick

[Doddy]

I'm impressed with the inverter - the manual claims the electrolytic caps within are "wearing parts" and must be replaced after 5 years.

At least they're honest.

[Clive S]

Great minds think alike

http://www.cnczone.com/forums/chines...52398-cnc.html

[magicniner]

I'm impressed with the inverter - the manual claims the electrolytic caps within are "wearing parts" and must be replaced after 5 years.

At least they're honest.

That's interesting, I have a couple of 1hp Siemens VFDs which are well over 10 years old and get daily use, standards must be slipping ;-)