PWM 0-3.3V Convert to DC 0-10V. Max Current 10mA

Other Hardware General Electronics
1

Hi,

I want to control an external System, which needs a variable 0-10V DC Input for controlling. I am able to put Software PMW to a Pin, nd controll ist varable as I need, but I need to Convert the Output from the board form PWM Modulation to DC, an also Step Up Output ESP8266 PWM 0.0-3.3V to DC 0-10V.
Max Current runnig over the Output is 10mA, so I hope not to need external Power Supply.

Is there any ready to use Part for this, which I can order?

Tanks,
Christoph

2

I doubt there is any ready made part for this. You could use a small dc-dc boost converter to provide a constant 10V supply from 3.3V/5V, then a transistor to boost up the pwm signal to 10V, and finally a low-pass filter to smooth the pwm into an analog DC voltage.

3

I'd look at an OpAmp, 3.33x gain. You can use a 12V supply if you have it available, do the smoothing at the input side.

Most OpAmps can source 10 mA, pick one that can source/sink 20 mA to have a bit of a buffer.

4

Hmm, yes. After my post I thought maybe drawing 10mA from the low pass filter would alter it's output voltage. So a better design may be to filter the esp output pin directly to create a 0-3.3V analog voltage, then feed that into an op-amp, because the op-amp will have a very high impedance input, so won't affect the filter's output voltage. Power the op-amp with 12V from a dc-dc boost converter if no other 12V supply is available.

5

Most 0 - 10V analog inputs draw almost no current so you should be able to use a 4.7k ohm/4.7uF RC LPF.

6

Great!

Thank You.

But - sorry - I am software spezialist, no hardware. How to wire?

Christoph

7

RC LPF

8

creiter:
Max Current runnig over the Output is 10mA

Did you actually measure that yourself yet? If, in fact, the current is much less than 10mA, like less than 1mA, then the simpler transistor circuit I suggested, along with the RC values suggested by raschemmel, might work. But if 10mA is truly needed, then the op-amp circuit suggested by vwmarle would be better.

9

This statement makes no sense when discussing a 0 to 10V analog INPUT

Max Current runnig over the Output is 10mA,

(because they are high impedance, as mentioned)

10

Thank You! I will try it out. Christoph

11

want to control an external System, which needs a variable 0-10V DC Input for controlling.

Some of these 0-10V inputs have the 10V already built-in wit an internal pull-up resistor. That way, you get full-brightness with no connection to the dimming input, or you can just connect a pot for dimming.

So, check with your meter to see if you already have 10V. If so, you can simply connect a transistor (with a current-limiting resistor to the transistor base).