http://www.circuitstoday.com/dc-motor-controller


Hi all,

I only want to know, before wasting time and money, if there's no mistakes in this schematic.

Thanks a lot for your help.

jm

 

I would have been inclined to use Mosfets now for motor control, a little more efficient.
Max.

 

Thanks a lot.

What type of Mosfets, before spending money to my electronic parts supplier?

jm

 

I would have been inclined to use Mosfets now for motor control, a little more efficient.
Max.

N chanel Mosfet like:

http://www.reichelt.de/Transistors-...A=2&ARTICLE=41636&GROUPID=2891&artnr=IRF+840S

Datasheet:

https://cdn-reichelt.de/documents/datenblatt/A100/IRF840#IR.pdf

Must ad 10 Ohm resistor before Mosfet gate?

Thanks a lot.

jm

 

What's your purpose for the motor?
Why you want to using manual to control the direction of motor?
How are the V/I for the motor?

 

What's your purpose for the motor?
Why you want to using manual to control the direction of motor?
How are the V/I for the motor?

Thanks a lot for your reply,

In fact, i want only to drive a dc motor, for a roadbook: power output from a Yamaha 500 XT + bridge for dc current.

Something simple, not only a DPDT switch to get forward and reverse ...

For this motor, say about 20- 30 W, to be sure.. 12V output

Actually, i've measured motor current - with no charge - result: 50 mA.
But surge ? nominal current times 5 or 6?

Maybe this motor is too weak, for driving roadbook rollers and map, so I'd be wise to see larger - range 20 -30 W -....

Regards.

jm

 

IRF840 is for high voltage over 100V and low current around 2~3A, it's not for low voltage under 40V 5A~10A, because almost low voltage mosfet always has a low resistance Rds(on) less than 20 mΩ, as 18mΩ, 14mΩ, 9mΩ, 8mΩ, 5.3mΩ, 4.5mΩ, 4.2mΩ, 4mΩ, 2.4mΩ, etc...

Vds -- choosing a rating voltage at least 1.5 times to +V power source, but if you can choosing >2.5 times is better.
Ids -- choosing a rating current at least 2.5 times to what load needed, , but if you can choosing >4 times is better.
Go to mouser or some other online seller to searching the Vds/Ids as above.

 

IRF840 is for high voltage over 100V and low current around 2~3A, it's not for low voltage under 40V 5A~10A, because almost low voltage mosfet always has a low resistance Rds(on) less than 20 mΩ, as 18mΩ, 14mΩ, 9mΩ, 8mΩ, 5.3mΩ, 4.5mΩ, 4.2mΩ, 4mΩ, 2.4mΩ, etc...

Vds -- choosing a rating voltage at least 1.5 times to +V power source, but if you can choosing >2.5 times is better.
Ids -- choosing a rating current at least 2.5 times to what load needed, , but if you can choosing >4 times is better.
Go to mouser or some other online seller to searching the Vds/Ids as above.

Thanks a lot first,

Like this one from my electronic parts supplier:

http://www.reichelt.de/index.html?ACTION=3;ARTICLE=41757;SEARCH=IRL 3803



For Rg resistor:

http://www.reichelt.de/1W-5-1-0-Ohm...3&LA=2&ARTICLE=1770&GROUPID=6514&artnr=1W+1,5


Regards.

jm

 

Thanks a lot first,

Like this one from my electronic parts supplier:

http://www.reichelt.de/index.html?ACTION=3;ARTICLE=41757;SEARCH=IRL 3803



For Rg resistor:

http://www.reichelt.de/1W-5-1-0-Ohm-820-Ohm/1W-1-5/3/index.html?&ACTION=3&LA=2&ARTICLE=1770&GROUPID=6514&artnr=1W 1,5


Regards.

jm

Assuming that you using Ids=5A then
Vds=I*R=5A* 6mΩ=30mV.
Wds=V*I=30mV*5A=150mW.
Normally I will using the Ids less than rating current and only 1/5 rating current.

The current of IRL3803 is great than I bought IRF1010EPbF.
IRL3803_Nch_30V140A200W_6mΩ.
IRF1010EPbF_Nch_60V84A200W_12mΩ.

 

Thanks a lot.

Regards.

jm

 

The DPDT switch in the diagram should have a centre-off position to allow the motor to come to a stop before rotation reversal. "Hesitation" switches are often used in this type of application. If you reverse the rotation of the motor without stop, your driver transistor and motor will not last long. E

 

The DPDT switch in the diagram should have a centre-off position to allow the motor to come to a stop before rotation reversal. "Hesitation" switches are often used in this type of application. If you reverse the rotation of the motor without stop, your driver transistor and motor will not last long. E

Nykolas,

First thanks a lot for your advice.

DPDT switch bought for this purpose is:

http://www.reichelt.de/Switches-Roc...2&ARTICLE=105650&GROUPID=3275&artnr=HS+647+H2

Datasheet - in german - sorry, but i don't understand ...

https://cdn-reichelt.de/documents/datenblatt/C200/16-SERIE_600H-600NH-D.pdf


Regards.

jm