The right motor you posted that it seems has gear in it, you can turn around two motors, if the right one isn't that smoothly as left one then it should be has the gear.

The file size was too big, before you attach it remember to compress it to a appropriate file size next time, and the new circuit need to adding a Rbe for Q2, and adding another resistor Rc1 for the Vc1 of first transistor, the Rc1 should be connected to Vcc from Vc1 and it can be as:
1. Vcc=12V, Motor = 600mA/Ib1 = 600mA/10 = 60mA
Rc1=(Vcc-Vce1-Vbe2)/
Rc1= (12V-0.2V-0.9V)/60mA = 185 Ω,choose 180 Ω or 150 Ω

2. Vcc=12V, Motor = 500mA/Ib1 = 500mA/10 = 50mA
Rc1=(Vcc-Vce1-Vbe2)/
Rc1= (12V-0.2V-0.9V)/500mA = 222 Ω, choose 220 Ω or 200Ω

You should choose the Ic current of Q2 have 5 times of the required current as iC=600 mA then it should be Ic =3A.

And the Ic1 of Q1 = 60mA * 5 = 300mA.

So Q2_Ic2 = 3A or more.
Q1_Ic1 = 300 mA or more.

The circuit will be as below:

 

Pretty sure that if you are only using one 555 circuit for this, moving two motors alternately, you will need a separate transistor circuit for the other one. Your using a NPN for the first one, then you need a PNP for the alternate one. One would work with the 555 output high and the other when the 555 out put is low.

 

Pretty sure that if you are only using one 555 circuit for this, moving two motors alternately, you will need a separate transistor circuit for the other one. Your using a NPN for the first one, then you need a PNP for the alternate one. One would work with the 555 output high and the other when the 555 out put is low.

OK, thanks for the suggestions from u all, will try it and keep updating how the circuit is coming up.

 

As suggested am using one npn and one pnp transistor now. am trying with LEDs first. Npn setup is working fine,but pnp is not working at all.

Voltage across the base of pnp(where have connected emitter to supply,led at collector and output of pin 3 to base) is not dropping to switch it on.

 

As suggested am using one npn and one pnp transistor now. am trying with LEDs first. Npn setup is working fine,but pnp is not working at all.

Voltage across the base of pnp(where have connected emitter to supply,led at collector and output of pin 3 to base) is not dropping to switch it on.

Hey guys, can some one plz suggest how to amplify current. Am still struggling with pnp transistors. Am using 2N 3906 and 04 as Darlington pair .to run the motor but its generating only arnd .2Amp and motor is not running as it needs arnd .5Amp. Plz suggest how I can make it run. Am using 3v with 2100mAh battery.

 

 

Hi all somehow am able to make one motor run on and off using Darlington pair. But now am stuck with making 2 motors run in as table mode. Below is my schematic for one motor. Could someone suggest how can I put other Darlington pair to make both motors run in as table mode.

View attachment 87026

those dc motors use brushes, your actually turning on and off as it turns. that messes up the output of the 555. the darlington isolates the motor from the 555 and lets it do its timing thing.

 

View attachment 87609

Do u mean I shld put both motors on supply side. Am trying to use 2 npn Darlington pair on upper half and 2 pnp Darlington pair on lower half with connecting motor to grnd for pnp pair and to supply for npn pair.

 

Using two circuits that I drawn in the same time, then you can get A motor turn on and B motor turn off, and B motor turn on and A motor turn off, if that is what you want.

 

Using two circuits that I drawn in the same time, then you can get A motor turn on and B motor turn off, and B motor turn on and A motor turn off, if that is what you want.

OK surely today will try it. thanks a lot