hello guys,
i need please some help in identifying components on this circuit and discuss some functions
here are the pictures :
The 2 white pieces are 0.25 Ohm 5Watts power resistors
the little green one is a capacitor
edit :
yes, it seems to be a solenoid (maybe adustable ? )
I'm not sure about the IC.... maybe you can get rid of the paper on it and see if there is a ID number under it
alnath:
The 2 white pieces are 0.25 Ohm 5Watts power resistors
the little green one is a capacitor
why someone would use a 0.25 ohm resistor ?!!!
Ok so you've got the components identified. What is your next question?
why someone would use a 0.25 ohm resistor ?!!!
why not ? XD
sometimes, you just need it .... could be in order to measure (or limit) the current .....
why someone would use a 0.25 ohm resistor ?
5W 0.25 Ohms can survive 4 Amps ( and will show 1V then )
ok so first about the solenoid why is it used in circuits like this ? (it's an RC car circuit)
what i know about solenoid is that it is used for purpose of induced current
about the white resistor what's their real purpose ? i mean a 0.25 ohm very small !! even if it is a 5W
about relays: do i need a relay if i want to command a motor (12V) by arduino and for sure using a transistor ?
so the motor should be attached to the relay which is attached to the battery and the arduino, by giving command the relay should act here and close the circuit between the battery and the motor ?
correct my info please if there is something wrong
Inductors are used in rf for oscillators, filters, wave propagation.
firashelou:
1 -ok so first about the solenoid why is it used in circuits like this ? (it's an RC car circuit)
what i know about solenoid is that it is used for purpose of induced current2 - about the white resistor what's their real purpose ? i mean a 0.25 ohm very small !! even if it is a 5W
3 -about relays: do i need a relay if i want to command a motor (12V) by arduino and for sure using a transistor ?
so the motor should be attached to the relay which is attached to the battery and the arduino, by giving command the relay should act here and close the circuit between the battery and the motor ?
correct my info please if there is something wrong
1 : solenoids are (were ?) widely used in RLC circuits - especially in RC vehicles
have a look here RLC circuit - Wikipedia, and here RLC circuit - Wikipedia
2- already answered 
3- we know nothing about your motors, but it is unlikely that it can be driven directly by arduino , then you'll need something between the arduino output and the motor . It could be a relay, if you make sure that the relay itself can be driven by the arduino (it has to work at 5volts and need less than 40mA to switch on), it could be a transistor, a mosfet....
Maybe you could tell us what you want to do with that stuff :idea:
alnath:
1 : solenoids are (were ?) widely used in RLC circuits - especially in RC vehicles
have a look here RLC circuit - Wikipedia, and here RLC circuit - Wikipedia2- already answered
3- we know nothing about your motors, but it is unlikely that it can be driven directly by arduino , then you'll need something between the arduino output and the motor . It could be a relay, if you make sure that the relay itself can be driven by the arduino (it has to work at 5volts and need less than 40mA to switch on), it could be a transistor, a mosfet....
Maybe you could tell us what you want to do with that stuff :idea:
this is the relay i am using :
http://trade.e-to-china.com/company-c3EEFA/Wenzhou_Amon_Electrical-pEGGGD6/PCB_Relay_JQX_14FC_.html
it's written on it 30V i donno i guess it should work ? isnt the 30V for a DC the limits for a DC current or the point where u can make it work ?
i thought about putting a transistor in between the relay and my arduino pin
am i working right or totally wrong ?!
contact load:10A 240VAC/28VDC
this is about the contacts and the load you can connect to ! Then without informations about the motor..... 
Specifications are not very clear, they don't give the coil resistance, but they say 0.55W , then it is too much for arduino output. Then yes, you have to use a switching transistor between the arduino output and the relay . Which transistor and resistors needed depends on how you want it to work. Don't forget the "freewheel" diode in // with the coil of the relay
alnath:
contact load:10A 240VAC/28VDC
this is about the contacts and the load you can connect to ! Then without informations about the motor.....
Specifications are not very clear, they don't give the coil resistance, but they say 0.55W , then it is too much for arduino output. Then yes, you have to use a switching transistor between the arduino output and the relay . Which transistor and resistors needed depends on how you want it to work. Don't forget the "freewheel" diode in // with the coil of the relay
it didn't work donno if i was connecting it in a wrong way : i was connecting the 2 pins of the coil to transistor then arduino and GND
and the other 3 pins, one to GND , and 2 to the battery and motor
actully the motor all i know about is that it function with 12V battery series of 700mA
which transistor ? (PNP, NPN )
i was connecting the 2 pins of the coil to transistor then arduino and GND
and the other 3 pins, one to GND , and 2 to the battery and motor
I can't really "see" how you connected it, you should post a schematics
alnath:
which transistor ? (PNP, NPN )i was connecting the 2 pins of the coil to transistor then arduino and GND
and the other 3 pins, one to GND , and 2 to the battery and motorI can't really "see" how you connected it, you should post a schematics
i am using NPN transistor and i changed to relay and used one of those in the picture above
and these are the pictures for the relay
don't use the relay only , your arduino won't like it
please, post a schematics, you can draw it on a paper ad take a photo if you like, but the photos you posted don't really help
alnath:
don't use the relay only , your arduino won't like it
please, post a schematics, you can draw it on a paper ad take a photo if you like, but the photos you posted don't really help
ok i did a schematic sorry if i didn't use fritzing but not sure about if the relay is connected right i guess not because something which i felt very bad happened, the arduino wasn't connected to any power and it started flashing and motor working when i connected the relay that way like schematic but i disconnected it in a fast way after seeing that it took maybe a sec !! hope arduino's fine !
what transistor is it ?
where is the emittor ? base ? collector ?
what began flashing ??
are you sure the contacts you connected the battery+motor on are "NO" (normally open) ?
for now, I have to leave (dinner time here )
I'll be back
alnath:
what transistor is it ?
where is the emittor ? base ? collector ?what began flashing ??
are you sure the contacts you connected the battery+motor on are "NO" (normally open) ?for now, I have to leave (dinner time here
I'll be back
the transistor is : 2N3904
i made it work but i added another 2N2222 between the relay, battery and motor so is this something right to do if the battery was a 12V instead of 9V ?
why a 2222 in the battery/relay/motor circuit ?
not needed, and IMO, not a good idea ... and I don't see how you've connected it.
replacing the 3904 (which is a .6W only transistor ) with the 2n2222 or even a better switch transistor should work
alnath:
not needed, and IMO, not a good idea ... and I don't see how you've connected it.replacing the 3904 (which is a .6W only transistor ) with the 2n2222 or even a better switch transistor should work
ok so the 2N2222 is the best NPN transistor ?
and why because when i remove the transistor the relay just make a sound and the motor doesn't work but when i add the transistor the motor work in a perfect way so ?