You have apparently understood nothing we have said.

 

Yes, i understand this so the toggle button will off so the circuit power will off as well the thyristor

No, apparently you don't understand.
An SCR operates as a latch that will keep conducting even when the gate signal is removed.
It only stops conducting when its anode-cathode current stops.
Thus the switch to turn off the SCR needs to be in series with the motor and SCR.

 

Oh i got it, so the toggle switch should be before the motor

 

But how to connect the thyristor anode and cathode to the motor and the battery

 

Your power sources need to share common, I covered that. I gave you a basic schematic. I am sorry but most of the people who would like to help would appreciate a schematic. Reading a crayon picture is difficult at best. I have no idea what the red button is all about? Would that be N/O or N/C? As mentioned, once you turn a SCR On in a DC circuit it's on and remains on till the load power is broken. I have no idea what you are doing on the gate circuit? Go back and look at post #10 and work from that. Label your parts as to pinout and what the switches are.

Ron

 

 

But how to connect the thyristor anode and cathode to the motor and the battery

I told you that in post #8 and Ron gave you a schematic in post #10.

 

View attachment 276312

In this circuit, there is no lock function as SCR and the transistor missing the Rbe to turn it off, a floating Vb will cause oscillation.

 

Is that transistor symbol in post #26 supposed to be your SCR?
Is so, use an SCR symbol.

 

I'm not absolutely sure about thyristors and brushed motors. Will the commutator cause enough interruptions in the current to de-latch the thyristor? Does it depend on the commutator and the design of the brushes?

 

Is it right?

 

Yes, it can be done that way, but why?
Now you need two power supplies, and one is floating awkwardly at the cathode voltage, which could be either0V or 12V.

 

Yes, it can be done that way, but why?
Now you need two power supplies, and one is floating awkwardly at the cathode voltage, which could be either0V or 12V.

But voltage at these two point will be 1.5v as the second battery

 

View attachment 276336

Is it right?

To see the post on #10 posted by Ron, so you just need one voltage.

 

To see the post on #10 posted by Ron, so you just need one voltage.

Yes i know and i understood how to use it with one power supply, but i want to learn to use two power supply

As some applications will need more than power supply.

I just want to learn to use more than one power supply

 

But voltage at these two point will be 1.5v as the second battery

It will be the voltage drop across the gate-cathode junction; so something less than the 1.5V battery voltage.

 

It will be the voltage drop across the gate-cathode junction; so something less than the 1.5V battery voltage.

Can you please explain more or why will this drop will happen

 

Yes i know and i understood how to use it with one power supply, but i want to learn to use two power supply

As some applications will need more than power supply.

I just want to learn to use more than one power supply

So you need to know the Vg of SCR, you should compare two circuits.

 

View attachment 276337
But voltage at these two point will be 1.5v as the second battery

The voltage at the cathode will be 0V, and the voltage at the Gate will be about 0.8V when the switch is pressed.
About 1us later the cathode will be at 11.2V and the gate at 12.6V.

 

So you need to know the Vg of SCR, you should compare two circuits.

The maximum Vgt of this thyristor is 1.5v