Let's Make Robots!

Solenoid, Servo (?), relay

Hi all..! I've tried to install the picaxe 28x1 on a remote controlled car. I've just set the motor of the back wheels and they work.but there's a problem with the SERVO (?) that controls the frontwheels (and makes them turn).. 

this servo (?) has only TWO wires (not 3 like others) ..so, Gobliz,jklug80,thecowgod said that this i probably a solenoid, not a servo (thanx for helping guys) .. so here's the photo

 

relay5v_0.jpg

 

there are two wires, yellow and green...

 when the G is on the ground, and the Y is on the pin, it turns on right

 when the Y is on the ground, and the G is on the pin, it turns on left    ... and the picaxe28 has no program on..

is that a solenoid? in this case.. I've take 2 5volt relays.. how can I get they work? .. anybody can explain very simple how a relay works..? by the way anybody has a good site or materials to take some instruction of how read a circuit diagram? 

however here's some sheets of my relay.. http://www.rapidonline.com/netalogue/specs/60-0680.pdf is it the correct relay to use..? actually I have 4 aa connected to the picaxe28x1.. 

 thanx all .. 

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.
Is this any good to you? It makes a suggestion as to how you might control a solenoid to make a bot steer.
strange, 4 AA's should be enough (both 1.2v each or 1.5v) try putting pins 6 and 7 low before activating the motors. Oh by the way, when you make pin 4 go high and pin 5 go low everything works fine right ( i mean without also making pin 6 high and pin 7 low )?

success... it was a very.. very .. stupid thing.. and i've understood a lot of things doing this xD thanx all

 

 edit ... xD ... when I set "high 6 low 7"  (where the dc motor is connect) all ok. they turn. when I set "high 4 low 5 (motors) high 6 low 7" the wheels don't turn well.. just a little..

Yeah, that looks like a regular DC motor to me. So you could use the relay or an H-bridge/motor driver chip to control it.

Dan

I have a motor driver.. (L293D Motor Driver) . but I cannot figurate out where to connect that two wires.. could you explain how use the l293d? cause I think I'm not able to use the relays .. I don't know where to start (Ive only sold them to the perfboard..  xD)

 edit: 

the problem is that when i connect one on the ground and one on the pin it turns on a way, if I reverse pin and ground it turns the other way (without any program on the picaxe).. and I can't figurate how to control this by picaxe28..  

Any time you're working with a chip and need to know how to hook it up, the first thing to do is get ahold of the datasheet. Almost always, a quick Google search for the part number and the word 'datasheet' will get you a bunch of links for them in PDF format. Try googling for 'L293D datasheet' and you'll see plenty of sites that offer it. Read that document and it will explain which pins need to be connected where.

Dan

thanx dan, and thanx to the other, all helped greatly (does the word greatly exist?). I will try to connect that dmnd motor xD

ooh ok i remembered their usage in RC cars! they are used to pull the string front wheels are attached to. still, that doesn't really look like a solenoid, especially because it turns a wheel in that little space

 

edit: Nah! that's just a dc motor, i just looked at the pictures again and it really looks like a standard dc motor. Just attach your relays to it and it will be fine. (anyways...it wouldn't be much important whether it was a motor or a solenoid, you just attach it to a relay and it will work.)

Solenoids are basically copper wire wound around a metal bar. When the copper coil gets current it turns magnetic and draws the metal bar inward. When the current is gone a spring pushes the bar out. This gives lateral movement. That's all I got to say about solenoids. I've never used one in a project ;)

a relay is something that works as a switch, thus for switching on stuff like motors. But you're not turning them on and off with your hand but with electric current. So basically, if you apply some current to them they will switch on other things (like motors for example). in a sense they are amplifiers, cause with a low current you can control a bigger one (i want to put a special stress on the word "in a sense").

By the way you can find an insight on relays (how to hook them up and use them) here: http://letsmakerobots.com/node/928 credits go to Frits (thus you may be find them with other names, such as turn-on-and-off-thingeys (old form of danish english) )

as for the solenoid...well, i thought solenoids were other things actually (not motors). As far as i know that could look like a standard DC motor, but i do not want to add more, you better wait for a better answer about it.