* THE FORUM FOR ALL THOSE INTERESTED IN BUILDING AND OPERATING MODEL SUBMARINES *



Join the AMS - Registered Forum users can become members of the AMS and it's free ...... To join register on the forum first then follow the forum link to our membership form which is on our website


For further details of any events shown here also see the "Shows and Events" section on the forum

*STOP PRESS* Coronavirus. A lot of Clubs have already cancelled all activities. Check carefully before you plan any travel

.

CANCELLED because of coronavirus. Papplewick Pumping Station, Nottingham, Sunday 12th & Monday 13th April
CANCELLED because of coronavirus. Bournville Sub Day, Sunday 10th May 2020

. ,

Submarine, Boating & Sailing Weekend, Norwich MBC, Weekend of 25,26th July

,./
.
Model Boat Convention, Haydock Park (Cancelled this year)

.

Bournville Sub Day, Sunday 13th September

,,,,

Club Submarine Regatta, Furness MBC, Barrow in Furness, Sunday 20th Sept 2020

Who is online?

In total there are 3 users online :: 0 Registered, 0 Hidden and 3 Guests

None


Most users ever online was 180 on Tue Nov 05, 2019 6:03 am

Latest topics

» today's work
Transmission of servo (pwm) signals through water and clear plastic EmptyWed Mar 25, 2020 2:14 am by merriman

» British Submarines in Two World Wars by Norman Friedman publ by Seaforth.
Transmission of servo (pwm) signals through water and clear plastic EmptyTue Mar 24, 2020 11:27 am by david f

» Telemetry on openLRS
Transmission of servo (pwm) signals through water and clear plastic EmptyMon Mar 23, 2020 1:21 pm by david f

» stretching sprue
Transmission of servo (pwm) signals through water and clear plastic EmptyThu Mar 12, 2020 1:13 pm by merriman

» RC for Submarines
Transmission of servo (pwm) signals through water and clear plastic EmptyFri Mar 06, 2020 11:06 pm by salmon

» Arduino proportional control of a piston tank
Transmission of servo (pwm) signals through water and clear plastic EmptyThu Mar 05, 2020 2:30 pm by david f

» Looking for Paint Colour Advice
Transmission of servo (pwm) signals through water and clear plastic EmptyWed Feb 26, 2020 10:30 am by david f

» Voltage or data measurement by WiFi - Node Mcu (Arduino) - A failed experiment
Transmission of servo (pwm) signals through water and clear plastic EmptyMon Feb 17, 2020 11:10 pm by C-3PO

» U Class British - ORP Dzik ( built in Barrow)
Transmission of servo (pwm) signals through water and clear plastic EmptyWed Feb 12, 2020 12:54 pm by david f

Statistics

Our users have posted a total of 11096 messages in 1817 subjects

We have 845 registered users

The newest registered user is exceed

    Transmission of servo (pwm) signals through water and clear plastic

    david f
    david f
    AMS Treasurer

    Posts : 2082
    Join date : 2010-11-10
    Age : 69
    Location : Cumbria

    Transmission of servo (pwm) signals through water and clear plastic Empty Transmission of servo (pwm) signals through water and clear plastic

    Post  david f on Sat Jul 05, 2014 12:43 pm

    I am just putting the components away for something I was trying with the original Darnell XXI. I originally needed to send a servo signal through a clear, flat plastic hatch. I dropped the idea later as you will see in the Darnell XXI thread.

    But the method I tried worked well and was very simple.

    The sender unit (connected to the receiver) was just an Infrared LED with a 30 ohm resistor in series (just to limit the current. The receiver unit (connected to the servo) was a photodiode with a 1 megohm resistor in series. (The LED and photodiode were a matched pair but I can't remember where I bought them from. Ebay probably.)

    The early trials were surprisingly successful with the signal being happily beamed through several mm of plastic or even water.

    If you used a separate 5v supply at the receiver end then that is just one wire to transmit a servo signal.

    David

    salmon
    salmon
    AMS Forum Owner

    Posts : 296
    Join date : 2011-09-02
    Age : 60
    Location : Las Vegas, Nevada - USA

    Transmission of servo (pwm) signals through water and clear plastic Empty Re: Transmission of servo (pwm) signals through water and clear plastic

    Post  salmon on Sun Jul 06, 2014 7:35 pm

    Is that all it took was a resistor connected directly to the infrared led? No complicated circuits? Am misunderstanding?
    Thank you for posting this! Makes the brain work.


    _________________
    If you can cut, drill, saw, hit things and swear a lot, you're well on the way to building a working model sub.
    david f
    david f
    AMS Treasurer

    Posts : 2082
    Join date : 2010-11-10
    Age : 69
    Location : Cumbria

    Transmission of servo (pwm) signals through water and clear plastic Empty Re: Transmission of servo (pwm) signals through water and clear plastic

    Post  david f on Mon Jul 07, 2014 2:40 pm

    Yes, it really is that simple. I've just connected it up again to remind myself.

    One side of the photodiode (the side without a flat on it) is connected to +5v.
    The other side of the photodiode is connected to the white signal wire of the servo and one end of the 1 megohm resistor. The other side of the resistor goes to earth. (It's a pull-down resistor.)

    To "connect" the signal wire you would just need to push the led and diode into the end of ,say, some silicone tube.

    It should have wide application to model subs but, in my case, I bunged everything in a single WTC so the need for it disappeared!

    It is not particularly original - I'd seen the idea somewhere on the web in connection with robotics perhaps as an "optoisolator". The real optoisolaters are no good to us because they are encapsulated in a single device.

    David
    salmon
    salmon
    AMS Forum Owner

    Posts : 296
    Join date : 2011-09-02
    Age : 60
    Location : Las Vegas, Nevada - USA

    Transmission of servo (pwm) signals through water and clear plastic Empty Re: Transmission of servo (pwm) signals through water and clear plastic

    Post  salmon on Mon Jul 07, 2014 3:01 pm

    Thank you David! I have heard that running a servo a long distance from the receiver causes problem with interference. This might be good for keeping a servo in a remote location on the sub. Definitely something to play with!


    _________________
    If you can cut, drill, saw, hit things and swear a lot, you're well on the way to building a working model sub.
    david f
    david f
    AMS Treasurer

    Posts : 2082
    Join date : 2010-11-10
    Age : 69
    Location : Cumbria

    Transmission of servo (pwm) signals through water and clear plastic Empty Re: Transmission of servo (pwm) signals through water and clear plastic

    Post  david f on Mon Jul 07, 2014 4:18 pm

    Your comment has made me think of something else.
    Long servo leads can indeed give interference. I wonder if the light signal can go down a fibre optic cable?

    David
    salmon
    salmon
    AMS Forum Owner

    Posts : 296
    Join date : 2011-09-02
    Age : 60
    Location : Las Vegas, Nevada - USA

    Transmission of servo (pwm) signals through water and clear plastic Empty Re: Transmission of servo (pwm) signals through water and clear plastic

    Post  salmon on Tue Jul 08, 2014 12:29 am

    Exactly what I was thinking!


    _________________
    If you can cut, drill, saw, hit things and swear a lot, you're well on the way to building a working model sub.

      Current date/time is Sun Mar 29, 2020 8:56 am