Polarity Reversing Switch Experiment
Intro: Polarity Reversing Switch Experiment
I want to make a simple polarity reversing switch but I hadn't a switch with 6 legs like this one at Instructables. I had a lot of resistors and a small DC motor. Finally I used 2 pieces of 62R resistors and a switch. This is how it works
STEP 1: How Does It Work?
I used two resistors with 62R. I connect each pole of the motor to +5V through a resistor. My first experiment with GND on right side of the circuit results the motor turns right.
During the second step the motor turns left.
So if I insert a switch I can turn the motor to rotate right or left.
During the second step the motor turns left.
So if I insert a switch I can turn the motor to rotate right or left.
STEP 2: Some Calculations ...
I want to understand what happens so I started to calculate the paralell resistors value. You may find here a paralell resistor value calculator.
I tried with resistors 3R - 10R - 33R - 62R. They all worked but resistors lower than < 62R were warmed.
With 100R resistor it doesn't work.
The R3 resistance of the motor is 12R. So total I had 12R (motor) + 62R resistor = 74R.
Rtotal = (R2 + R3) * R1 / (R2 + R3) + R1 = (62 + 12)*62 / (62 + 12)+62 = 33.7
I tried with resistors 3R - 10R - 33R - 62R. They all worked but resistors lower than < 62R were warmed.
With 100R resistor it doesn't work.
The R3 resistance of the motor is 12R. So total I had 12R (motor) + 62R resistor = 74R.
Rtotal = (R2 + R3) * R1 / (R2 + R3) + R1 = (62 + 12)*62 / (62 + 12)+62 = 33.7
STEP 3: The Polarity Switch
I measured the total resistance and there is some difference between theoretical and practical result (33R and 37R). But all in all the switch works and I made my XANAX.
Don't you know what xanax is?
It is a sleeping pill "developed" by the old man from Emir Kusturica's movie Promise Me This. Here is a sample on youtube.
Don't you know what xanax is?
It is a sleeping pill "developed" by the old man from Emir Kusturica's movie Promise Me This. Here is a sample on youtube.
9 Comments
DieCastoms 10 years ago
I have to hand it to you that I have never seen this done, and I am impressed with it, even if there IS power loss to the motor and power drain straight to ground, but you ALSO get something else, automatically, that could be useful and in the right application, possibly a pro to outweigh other cons: Resistive Braking. With the series of resistors from pole to pole on the motor, your motor stops very quickly, as shown in the vids. This is the same braking technology as is used on virtually all modern locomotives.
Ikssk asked about using diodes, and Lemonie gave a clear and concise answer .. No. But ..... why not? Oh ... wait ... I just answered my own question while typing it . There would be no way to orient them for both states without switching their orientation when the state changes ....
"DC"
dac_cast 10 years ago
How much power did you input
bkb2 10 years ago
I used 5V and a cheap DC motor disassembled from a toy or a CD drive or printer. :-)
A photo from my motors used in this experiment.
s 12 years ago
ikssk 12 years ago
lemonie 12 years ago
No.
L
louis.m 12 years ago
I used this concept for DC motors on a three rail model railroad for many years.
domints 12 years ago
lemonie 12 years ago
For a way of avoiding the better solution of a switch, this is interesting.
L