[/b]does any one know how i can controll the speed on a small motor like a remote controll car motor:!:!!! is there a kit i can buy or maybe schamatics or a link with very detailed information the tought is to make one then be able to recreate one at a very inexpensive cost. ive been reading on this subject on other forums and the thing is i dont understant what they are saying
so somebody got a link for me or something i want to use this to speed up motors like on a robotic arm or slow down the mottor once it is build. like a current reducer or something from a 9 volt battery up to an ac adapter any info will help
To control DC motor's direction and speed you have to be familiar with H-Bridge and PWM ..
Do search on GOOGLE to find out more info on these terms .. http://www.mcmanis.com/chuck/robotics/tutorial/h-bridge/ **broken link removed**
Here is a practical example on motor control (H-Bridge and PWM) using a joystick (A/D conversion):
Also, you may need to learn a little bit about microcontrollers ..
The above example is based on PICAXE microcontroller, which has build-in PWM function, so, instead of starting from scratches, you just call PWM in program ..
Code:
PWMOUT pin, period, duty cycles
;- Pin is a variable/constant which specifies the i/o pin to use.
;- Period is a variable/constant (0-255) which sets the PWM period
;(period is the length of 1 on/off cycle i.e. the total mark:space time).
;- Duty is a variable/constant (0-1023) which sets the PWM duty cycle.
;(duty cycle is the mark or ‘on time’ )
I know this is an old post, but if you are planning to use a 9V "transistor" battery, you are going to find it will have a very short lifespan. You need NiMH rechargable AA cells at least, as they have a very high current capacity and discharge rates.
Hope any of these two kits from United 7 technologies may help you. Both the kits comes with 4 relays for 4 channels with Common, N/c and N/o contacts available through PBT connectors. The motors are requires to be wired in the correct sequence to work as required. The kits comes with complete documentation, schematics, PCB's, required components, and the component layout which helps you to construct and work the kit. More details and other projects may be seen at www.united77.com/projects.htm
1. RF based 4 channel Remote controller based on “Holtek” En/decoders
This is a remote controller which is widely used in robotic application where in momentary mode, 4 channels are available. Receiver side is equipped with four relays at the out put which can be wired in any configuration for the required operation. Individual addresses can be selected to operate more than one remote kit at a time.
2. Multipurpose Four channel RF Remote with 89C2051 Microcontroller.
This is a remote controller which can be widely used in robotic application when in momentary mode. All the 4 channels can be individually programmed as latched outputs for lighting loads or momentary outputs for bell or any other automation requirement. Receiver side is equipped with four relays at the out put which can be wired in any configuration for the required operation. 4 individual addresses can be selected to operate more than one remote kit at a time.