Need to be able to control speed of a 17 volt DC motor

[DW850]

Hi,

I am completely new to electronics whole topic and would greatly appreciate your help.

I have a heat gun that utilizes a 17 volt DC motor to move the air and would need to reduce the air flow. I only know this information (I don't know how many amps the motor draws and I do not have a potentiometer).

I would like to reduce its speed and would like to know what the simplest way to go about it would be. Do I need to figure out the Amps? would it be enough for me to solder on a resistor between the motor contacts (+ or - ?) or do i need to use what is often referred to as a pwm (i guess for that i need to know the amperage).

I would greatly apperciate your help in this matter.

 

[Audioguru]

Of course you need to know the continuous running amps and the peak starting amps.

DC motor speed controls use a Pulse-Width-Modulation (PWM) speed control circuit instead of a huge expensive pot. Then the motor has plenty of torque.

Soldering a resistor beween the motor contacts will heat the resistor and will not affect the speed of the motor.
A resistor connected in series with the motor will slow it down but then it might not have enough torque to start running.

 

[KMoffett]

Be aware that the air flow in a heat gun also keeps it form burning up. Guns that allow reduced air flow also reduce the heater current at the same time. If you just reduce the motor speed the gun will over heat, and at best will open the overheat thermostat or blow the thermal fuse.

Ken