Simple Servo Controller

[@waynekinney3358]

Very great, many thanks! I am now using this on my N Gauge layout, tests work great with finescale 'finetrax' turnouts. I found you can do this for about £1.50 per turnout from Ali Express, including servo, controller (servo tester) and resistor. Surely the cheapest method of turnout control ever, maybe evening including wire in tube! Fantastic!

[@SkipFloyd]

Dave, I wanted to thank you for this. Long story short, I have created a program that talks to A USR-io88 8 channel relay board for a different project I have completed. I wanted the reuse the relay board to control 8 servos, but could not figure out how to make the servo turn fully, then with another click return to the original location. I took your design and used the relay as a substitute for the toggle switch. The wires that normally would be installed on the toggle switch are installed on the Normally Closed and normally open legs of the relay. When the relay is energized the servo spins fully, when the relay is DE-energized the servo returns to home. I have created a Windows program using C# programming language and Microsoft's Visual Studio 2017. Now I can use a touch screen tablet / laptop to control up to 8 servos on this particular board. I paid about $65.00 on EBAY for the board and it works great. Took me a while to figure out how to control the relays via code. Again Thanks for this video it pushed me in the right direction to solve a problem!

[@DaveBodnar]

Skip - that is great news and a very creative way to use the simple servo control unit - well done & thanks for letting us know what you have done. Congrats! dave

[@scentgrasslakerailway]

I am quite late to the video; thank you it was a great presentation of the information! An amazing idea!

[@stevecoops8025]

Also equally of note is that these servo testers can drive three servos at once so a crossover junction can be changed with one switch.

[@stevecoops8025]

Interesting, I was looking into doing something similar. There is a 555 circuit out there but if something is ready made apart from the resistor, then that could be easier than some.

[@w.rustylane5650]

Thank you for this video. I've been wanting to power switches cheaply and you've hit the mark with me. Thanks again. I love your videos.

[@DaveBodnar]

Thanks for your kind words, Rusty - good to hear you liked the video dave

[@w.rustylane5650]

Awesome video. Thanks for sharing. I plan on doing this for my new layout, but I plan on using an Arduino to control relays to control the servo motors.

[@DaveBodnar]

You shouldn't need the relays as the Arduino can control servos directly. dave

[@w.rustylane5650]

Thanks for the info. I didn't know that it would power the servos directly.

[@w.rustylane5650]

Thanks, mate.

[@thecarpfather5757]

Could this be used to flip a motorcycle plate

[@Kevincsmith0708]

NiceJob Dave, ordered the controller last week, waiting on a slow boat from china.. After testing this out what would really be nice is to have the Servos thrown via the DCC++ Base station and JMRI. ;^ )

[@olacarpe6676]

Hello, great video 👏 I have a question, is it possible instead of the tester to put the servo motor on an RC transmitter and be able to use a switch, how did you do it?

[@DaveBodnar]

You could connect the servo to a RC receiver and use one of the transmitter controls to move it dave

[@olacarpe6676]

@@DaveBodnar Thank you very much for responding. Yes that I know. Can I plug the tester into the receiver?

[@DaveBodnar]

@@olacarpe6676 I do not think so dave

[@laurensiemens1436]

Hi...I was wondering if you can use the servo by itself...without the electronics. Trying to save some money

[@DaveBodnar]

A servo needs some sort of electronic signal to get it to move - applying power alone does nothing dave

[@terrydanca2438]

hi Dave, I just recently purchased 30 of these guys off e-bay to re-do all my point motors. it seems like the people who manufactured this servo tester must have changed something in the engineering. the problem I have is as follows. while they work fine just as your video- after selecting the rite resister and adjusting the throw. if you turn the power supply off to resume at a later time. when you power up the servos do a complete cycle turning the servo arm almost 320 degrees. I tried ten different servos and five different power supplies. 3V- 5V-.5.5V and 6V DC wall plug power supplies and a 5 cell R/C flight pac battery, all giving me the same results. also when I compare the circuit board that i have with the one in your video there are definite changes although the blue package covering, yellow knob, led's, selector switch and lettering are identical to what is shown in your video. please help, I purchased 30 of these 30 servos and spent a ton of time building a control box for everything,,,thanks Terry D

[@DaveBodnar]

Terry, sorry to hear that the operation has changed. Best bet is that another manufacturer copied the circuit and made some changes. I purchased some from Amazon the other day. I'll see how they work. Thanks for the information

[@terrydanca2438]

@@DaveBodnar I was trying to email something to info at train electronics and it wouldn't go, do you have an e-mail that I can send some pics of the board that I received?

[@DaveBodnar]

@@terrydanca2438 [e-mail]

[@myhobbies5965]

Sir, you have any idea which IC is used in this servo tester?

[@CALSASH]

Great idea. Is it possible to feed to LEDs on a panel to show which way the turnout was switched using this method?

[@DaveBodnar]

You would have to do that yourself - you could use a double-pole-double-throw toggle switch with one of the poles moving the servo and the other set doing a red and green LED. dave

[@CALSASH]

Thanks for the info Dave.

[@walidkhier]

The idea itself is brilliant. However, servos are active even in they are not moving. They consume power and their service life. Ideally, you would switch off the servo after each use.

[@DaveBodnar]

You are correct and make a valid point - thanks! dave

[@losi5ivet29cc]

@@DaveBodnar This is why they make what they call gear or retract servos for model airplanes. The servo will go to the desired position and stay there without consuming power and potentially burning itself out until the switch is moved to go into the opposite direction. A normal servo used on elevators and ailerons etc which I assume you have will always want to recenter itself when the stick is let go so if you you keep it in one direction for too long you use up the available power and potentially burn the servo out. Now I'm somewhat rusty on servos because I haven't played with a model aircraft or car etc in a while but I do know that a regular model airplane servo does not like to be held in position for too long because you can potentially burn them out even if the linkages etc are not adjusted properly it causes the servo to hunt for centre when centered or fight the command given. This is why they make the retract servo for model airplanes as it is designed to stay in the desired position until the command is given to go the other side. I would think a retract aka gear servo as it is better known would be a better option for this application as the servo itself will not want to recenter itself or Hunt for centre all the time. Hope this made some sense and helps? Thanks.

[@DaveBodnar]

That is great information - I did now know about such servos - will check them out - thanks! dave

[@losi5ivet29cc]

@@DaveBodnar You are very welcome!

[@robertschworm6036]

Dave,. How did the thunderstorm app work out with the lightning and sound delay? Bob s

[@DaveBodnar]

Bob - it worked out rather well - details on my web page here www.trainelectronics.com/Animation-thunder-lightning/delay.htm dave

[@jeffmcclain1894]

Can a two step process be used? I would like to use a momentary switch in conjunction with the toggle to only power the servo motor during the switching movement.

[@DaveBodnar]

Jeff McClain I don't see why not, Jeff give it a try and let us know what you find Dave

[@jeffmcclain1894]

Follow-up answer. The two step process works great. A DPDT toggle is wired to the potentiometer and a momentary button switch to the power input. The potentiometer is turned full on to mount the servo to one side if the switch. After mounting turn down as required to switch to the other side. I hot glued the knob to maintain this position. Flip toggle then push momentary switch and switching occurs. A micro-switch mounted with the servo and actuated by the arm is wired to position LEDs on the fascia. The other side of the toggle is wired to the frog. A short will happen if toggle is flipped and button is not pushed. A safety push of the button during approach will lessen the risk. The beauty of this is two-fold. No computer input required and an overloaded servo will not continue to make noise or burnout. Oh and by far this is the cheapest way to electrify switching.

[@leost-rexfans3984]

do you have the arduino code to share?

[@DaveBodnar]

There is no Arduino used with this project - the controller is pre-programmed

[@abhishekw]

Hi Dave, First of all thanks for this simple trick to drive the servos!!!! I was figuring out if we can slow down the throw speed of the servo? I want to have a slow movement of the switch... please advice Thanks Abhishek

[@DaveBodnar]

Abhishek - the speed of the throw can't be changed with this controller - you would have to move to a PIC or Arduino or similar controller to vary the speed. dave

[@abhishekw]

Dave Bodnar Thanks a lot for a quick reply!!

[@abhishekw]

kzbin.info/www/bejne/hmizdX2LfdWEmNE&feature=share Any idea how the schematic would be for the circuit in this video? Is it achievable like this?

[@DaveBodnar]

I don't have a schematic but a search for "555 servo circuit" should get some results for you. dave

[@abhishekw]

Dave Bodnar Thanks a lot!!!

[@melfackler1341]

Dave, you mentioned using a higher value resistor for shorter throws of switch. I am using N scale. Is there a resistor size you might prefer for that gauge? I don't know what I am doing here! Thanks again, Mel

[@DaveBodnar]

Mel - the value of the resistor has nothing to do with the gauge - It only sets the throw of the points - just experiment with resistor value until you get something that works for you. Good luck & enjoy! dave

[@waynegrauel1031]

Dave.. Just saw these controllers on eBay and thought the same thing. You saved me wondering if they would work. I have a bunch of rc servos laying around. Question.. Is it feasible with this mod to wire another servo in tandem ( with a Y ) to control 2 switches. Assume servos would have to be identical. Thanks again. Just decided to wire up some trains. Looking forward to your other videos. Wayne

[@DaveBodnar]

Wayne - I have used the controller with multiple servos (there are 3 sets of output pins so that is easy to do) - just make sure you provide sufficient power (current) to drive them all. Enjoy! dave

[@BriansModelTrains]

Great work Dave!

[@adamtant1302]

Dave,I am trying to do the same as you do. I am also trying to install switch point detection, either for normal point or reverse point condition. Have you tried anything for point detection?

[@DaveBodnar]

I have not done any such tests, Adam - please let me know how your experiments go dave

[@adamtant1302]

Sure, definitely. If point detection works, my plan is to cascade point detection relay back contact in series to energy path, so energy can be cut when switch completes its move.

[@adamtant1302]

Right now, just waiting for relays and parts to arrive and detailing.

[@fruferSK]

how many servos/basically railroad switches can be operated with one servo tester? I couldnt find it in product description.. it has 3 outputs, but as i saw in video, youve soldered the switch direct to the board.

[@DaveBodnar]

You should be able to operate 3 or more so long as you provide sufficient power Give it a try! dave

[@fruferSK]

and where to connect other 2 throw switches? I was thinking about to cut off the -IVE and +IVE wires to servo and solder the switch there. is it a way? you know, i am not electrician.. next one thought - do i need to use throw switch or on-off-on switch??? jeez, so many questions...

[@DaveBodnar]

You should connect the other servos wired in parallel with the first one - the other two servo connections are wired that way. Any normally open single-pole-single-throw switch will word. dave

[@railbuilderdhd]

Have you or is there a way to run this with the DCC model railroad system?

[@DaveBodnar]

Dave - I have not tried using this with DCC but you surely could if you set up your DCC controller to operate a relay to change the servo's direction - just put the relay in place of the toggle switch. dave

[@brickleyyard4966]

And u could keep this on a separate power fed and orporate the points manually and the trains dcc as that's how I will be doing mine So hears my question what voltage is save for this as the power from the controller with I think it's called a cdu would be 12 volts so would it be save to do that

[@melfackler1341]

Dave, thanks for the video. I have a question tho. What did you use for power supply to the tester?

[@DaveBodnar]

Mel - You can use a voltage from 3.5 to 5 volts - I used a 3.7 volt cell phone battery for some tests - you could also use a cell phone charger as most put out 5 volts DC dave

[@miljcha]

What will happen if I do not put a resistor?

[@DaveBodnar]

If you left out the 4.7K resistor the servo would move to one extreme --- the value of the resistor determines how far the servo goes in one direction and the adjustment of the potentiometer sets the other direction movement.

[@jeffmcclain1894]

I will not be using the resistor. Simply leave the potentiometer at zero. Mount the servo so that zero is one side of the switch and the added potentiometer value is the other. When the toggle interrupts the circuit it returns to zero.

[@waynespencer4247]

Hi Dave, Just found your channel having just bought 10 tower micro servos to operate my peco points but not knowing how to control them. I will now order 10 servo testers at £1.02p each ,would i be able to operate signals at the same time as a point ? Regards and thanks for a great tutorial

[@DaveBodnar]

Good to hear you found the info of value - to operate signals you would need to add some circuitry or have the servo's arm hit a switch as well as throw the points - doable for sure but a bit of experimentation is in order! dave

[@waynespencer4247]

Hi Dave, Thanks for your reply, just a question about the spdt switch is that a on off switch or on on switch probably a daft question but had to ask. Regards Wayne.

[@DaveBodnar]

You don't even need a SPDT as a SPST (single pole, single pole) switch will do - it is an on/off switch dave

[@aaron31659]

Hey man, I know nothing about working with servos, but I see potential to put something like this on the side of a drone for a payload release (basically a servo moves an arm holding a ring in place, the ring is connected to an object that is then dropped with a drone.) I own none of the parts for a settup like this. so what would I need? so far I believe I need a resister, servo, servo tester, and switch (i will be using a light detecting resistor so I can hook this up to an LED I have on my drone that is controlled from the controller). what type of power should i be using? is there any way to do this with a standard battery such as an AAA?

[@DaveBodnar]

You might need some additional circuitry to get it to react to the LED - perhaps a transistor to amplify the output from the light sensor. It is surely worth some experimentation. Good luck and drop a note to let us know how it goes. dave

[@aaron31659]

thanks man! but whats the cheapest battery you recommenced for this?

[@DaveBodnar]

Three AA cells wired in series should do it - if weight is an issue you could use AAA cells dave

[@aaron31659]

awesome. Thanks!

[@thomasdonking8157]

Aaron Fowler a

[@DaveBodnar]

I do not I'll see if I can figure it out tomorrow

[@DaveBodnar]

My Hobbles, I took a look at two different servo testers and there is no information engraved on the mircoprocessor - one is an 8 pin surface mount and one is a 14 pin - there are any number of generic chips that could be used but no clues inside! dave

[@matokaroly2874]

Do you speak Hungarian?

[@DaveBodnar]

I do not

[@moacirdasilvavieira6978]

Thank veri good circuit for modem desvio tren.