RC Servo Analog Control

[Croboy]

Halo people! I am very new on this forum. So without more ado this is my story:

I started a school project month ago. It 's about animatronic hand witch I had seen on youtube. It was all digital and complicated with mircochips and stuff.
I decided to make it parcticly "easyer" and to go analog way.


First I found out on some sides PWM controller with 555 timer. It was quite simple control over potenciometer.
I bought all the stuff and ordered 5 Modelcraft RS-2 Servos. Tryed 4 PWM analog circuits and nothing.

Servo acts same with, and without signal wire. Now I am quiet despreate and I need help.

BIG THANKS! (and sorry for bad english)

 

[poor mystic]

Hi
You need to post circuit diagrams and good quality photographs showing fine detail of both sides of all circuit boards.

 

[(*steve*)]

So you can't get your servos to work with the 555?

You need to show us the schematic(s) you've tried.

Preferably also show us a photo of one that is built up and (not) working.

Have you even built a 555 circuit that worked? (i.e. what experience do you have?)

 

[Croboy]

Hi
You need to post circuit diagrams and good quality photographs showing fine detail of both sides of all circuit boards.

http://pcbheaven.com/wikipages/images/howservoswork_1245432018.jpg

R1 is 6.9kOhms
R2 is 33kOhms
R3 is 470kOhms

Its all explained here http://pcbheaven.com/wikipages/How_RC_Servos_Works/

Another diagrams: http://www.sentex.net/~mec1995/gadgets/servo4.htm
http://www.555-timer-circuits.com/images/ServoController.gif

 

[Croboy]

So you can't get your servos to work with the 555?

You need to show us the schematic(s) you've tried.

Preferably also show us a photo of one that is built up and (not) working.

Have you even built a 555 circuit that worked? (i.e. what experience do you have?)

Few years ago I was making LED diode oscilator (It worked fine). I wasn't take photos from boards but I can make it on test board. I 'll make a video tomorrow.

 

[Croboy]

I forgot to say: If anybody had expirience with Modelcraft RS-2 let me know.

 

[(*steve*)]

try placing a 1k resistor (anything between 560 ohms and maybe 10k will be fine) between the transistor's emitter and ground.

I've not played with servos, but if this one doesn't have something to pull the input down, the transistor will not produce the waveform that the servo requires.

 

[Croboy]

try placing a 1k resistor (anything between 560 ohms and maybe 10k will be fine) between the transistor's emitter and ground.

I've not played with servos, but if this one doesn't have something to pull the input down, the transistor will not produce the waveform that the servo requires.

Thanks for advice... It doesnt work again. I think maybe can be connection problem with testing panel... I ll get new PCB on 1. March and start over again.

If that does not work again then it can probably be problem with Modelcraft RS-2.

THANK YOU ALL!