[ballistic42]

I have a sensor that needs 24VDC for power. My circuit board that the power signal is sent to can only handle 5VDC@24 milliamps. The power supply is 24vdc@5amps. Can someone smarter than myself enlighten me on a circuit board that I can install for a go between to knock the power down to the 5VDC@24 milliamps? If there is not such a board out there how may I make a board with resistors to do so?

Jeff

[sparkness]

your sensor should do the job. It will get wired for 24VDC The output of the sensor will switch the lower voltage provided that 24VDC power supply and the 5VDC have common grounds. Circuit shows an NPN type sensor

post photo of sensor and give more detail as to the circuit it will connect to

[ballistic42]

Ok not sure I said it good enough. I have a sensor that needs 24VDC to operate it. The power supply for the sensor I am using is 24VDC @ 5amps. So the sensor is being fed 24VDC. I need something in the form of a resistor (I am guessing) to lower the VDC comming out of the sensor (24vdc) to the circuit board (5vdc @24Ma). I cant put 24vdc @5amps back to the circuit board for the signal. So the signal wire that is carrying the 24vdc, has to have something in between it and the circuit board (cnc4pc C3 index board). Thanks for the input in advance....

[sparkness]

the circuit shown will do with no additional resistors provided your sensor is an NPN type 1. Connect your sensor output to the A terminal (cnc4pc C3 index board) 2. Connect your sensor neg to the E/K terminal (cnc4pc C3 index board) 3. Connect your sensor pos to 24VDC positive 3. Connect 24VDC neg to the E/K terminal (cnc4pc C3 index board)

[ballistic42]

Well I see what you are saying now but as luck would have it, it is PNP.....rats. Its a can of worms now...lol

[sparkness]

what are you connecting the (cnc4pc C3 index board) to ?

[ballistic42]

what are you connecting the (cnc4pc C3 index board) to ?

Goes to C3 to C52 via rj45 cable.

[ballistic42]

Goes to C3 to C52 via rj45 cable.

The C52 from cnc4pc is connected to a smoothstepper which is attached to a C32 board. I had to do this to get more I/O for my ATC and other stuff.

[sparkness]

what is the part number on the sensor it may very well connect with no problems

[sparkness]

smoothstepper is what I hav as well , they work good in my opinion

[ballistic42]

Here is the sensor.
https://www.automationdirect.com/adc...tion/MAE-AP-1A

[ballistic42]

Yes the SmoothStepper is great. I have it all maxed out though with all the 1, 2 and 3 ports used up. The ATC and all the air valves and the like took up a lot of I/O. Its nice and organized in my control box there is a lot going on inside there.

[jalessi]

PNP Prox Schematic

Use a 1K resistor for 24 volts

Use a 470K resistor for 12 volts

The resistor is dropping the voltage not the current.

[sparkness]

the cnc4pc C52 board has jumpers for pull down resistors that should be set and you will not need the c3 board , go directly into the C52 with the sensor.

[sparkness]

looking through the cnc4pc documentation you can connect your sensor to the c32 or the c52 board directly via the rj45's as jalessi shows in his schematic.Connect your sensor out (black wire) to pin 5 of the rj45 using the current limiting resistor shown

[ballistic42]

Guys THANKS a lot!!! I will head to the electronics store pick up some resistors. I do have a 12 vdc power supply that I could use instead of the 24vdc power supply. Question, the 24 vdc power supply puts out 5 amps will the resistor pull the amps down to 24Ma? My 12vdc power supply is only 1.67 amps, maybe that would be easier? The signal back to the C52 board can only handle 24Ma.

[jalessi]

Jeff

The current or amperage output capacity of the power supply is not the issue, only the voltage.

Jeff...

[ballistic42]

Jeff, would you recommend using the 12vdc power supply Vs. the 24 vdc power supply to make this happen?

[jalessi]

Jeff,

As long as you use the appropriate value (voltage dropping) resistor use 24 volts, overall the higher voltage is much more reliable and what I would be using if I chose to use a proximity sensor.

Jeff...

[ballistic42]

Jeff, Awesome!! I was looking on the net learning Ohms law and how to plug the numbers in to run the math. I see how it is working and where the numbers come from now. Thanks so much for the education and helping me. I dont really need to see the RPM on Mach3 but its just something that I want to see work. I am running a tread mill motor using the KBMM 225D board and it works well. The only issue I am having is the RPM's are off by 250 and that bothers me. I ran the motor up to full RPM and adjusted the trim pot on the C32 board to the 10vdc. I am using PWM as well. My max pulley RPM is 4000 and ratio of 1. In the mach3 ports and pins spindle setup I have base freq. 300 and 5 for %. I have tried everything and read until I am blue in the face but still cant get the thing to be right on the RPM that I tell it to go. I am using a hand held RPM tach to track the RPM. I have read the C32 lit. , the ESS smooth stepper lit, and the KBMM 225D lit but still nothing explains the rpm being off by 250. This sensor will help me narrow it down I hope.

Jeff