4 channel analog IC

[anneranch]

I am in an initial stage of "B17 props emulation".

I am looking for a way to
have a single analog output to control DC motor to emulate
starting of the engine
running of the engine with specific speed
optionally reversing the engine

IC solution preferred , open to "discrete" components ( 2N3904 ?)
Raspberry Pi ? Zero ?

 

[barry]

A pule-width modulated H-bridge would do it.

 

[KlausST]

Hi,

Electronics designers need some values like "voltage (range), current, frequency, error, ...."

What is a "B17 props emulation"?
What do you mean with "engine"? Is it a petrol engine?
You say "4 channels" but you speak of a "single analog output". This is confusing to me.
Where does this "single analog output" come from and where does it go to?

Maybe some more details, or some pictures / drafts could clarify.

I also don't understand the 2N3904 / Raspberry information...

Klaus

A pule-width modulated H-bridge would do it.

Now I'm even more confused.
A PWM is not analog, nor is an H-bridge analog (usually) ... nor do I see 4 channels (are these the 4 transistors of the H-bridge?)

Please enlighten me.

Klaus

 

[anneranch]

A pule-width modulated H-bridge would do it.

Sounds OK.
I need to RTFM but my guess is the polarity , hence motor direction reversal, is "iffy" .
Not without additional hardware - so maybe later.

These are tiny ELECTRICAL motors as used in toy drones.
I got one of them test running from small , about 4x4 inches solar cell,
I did not bother to test the voltage...

Pulsing them , the motors, should not be a problem.

PS since this is my first post here and I am not sure about this forum "culture" I will just ask / say this

Is this an electronic hobby type forum ?
Are pointless discussions , such as to answer silly questions, OK with forum managemt ?
B17 orignal engines are...not subject of my post )
( I prefer "just the facts ma'am... " - my opinion)

Cheers

 

[barry]

Hi,

Electronics designers need some values like "voltage (range), current, frequency, error, ...."

What is a "B17 props emulation"?
What do you mean with "engine"? Is it a petrol engine?
You say "4 channels" but you speak of a "single analog output". This is confusing to me.
Where does this "single analog output" come from and where does it go to?

Maybe some more details, or some pictures / drafts could clarify.

I also don't understand the 2N3904 / Raspberry information...

Klaus


Now I'm even more confused.
A PWM is not analog, nor is an H-bridge analog (usually) ... nor do I see 4 channels (are these the 4 transistors of the H-bridge?)

Please enlighten me.

Klaus

Would you say the output of a switching power supply is not analog because it uses PWM?

I proposed a solution to his requirements: variable speed, direction reversal. Relatively simple implementation.

 

[KlausST]

Hi,

Would you say the output of a switching power supply is not analog because it uses PWM?

The PWM is purely digital, just ON and OFF, not analog.
Then there is a low pass filter, usually an L and a C ...the output of the filter is analog. (Digital input, analog output)
No more ON and OFF but some analog variable voltage.

Klaus

 

[barry]

Hi,

The PWM is purely digital, just ON and OFF, not analog.
Then there is a low pass filter, usually an L and a C ...the output of the filter is analog. (Digital input, analog output)
No more ON and OFF but some analog variable voltage.

Klaus

Exactly my point. The motor acts as the filter in this case.

 

[KlausST]

Hi,

But how does this match to the OP's:

I have a single analog output to control DC motor

I take this signal like an analog signal coming from a DAC...

For small motors you may use an audio BTL amplifier to control the motor's RPM and direction. With the drawback of some dissipated power.

Klaus