24 March, 2011
Choosing the right type of controller / regulators for your vibratory feeders
There are various types of controllers / regulators which can be used for controlling the speed of a vibratory bowl feeder. These are voltage controllers, frequency controllers, constant voltage controllers and feedback controllers, double speedy controllers etc. When each of these controllers are to be used is given below –
- Voltage Controllers – These vary the amplitude or the voltage and some do have voltage compensation provision i.e. to keep the output same even if there is a spike in input voltage. Usually, depending upon the rating of the vibratory feeder, the controller has to be selected. Normally, there are controllers having ratings of 3 Amps, 6 Amps, 8 Amps and 10 Amps. A good controller should also have overload cutoff provision (to switch off the controller when the current drawn exceeds the pre-set limit). This is required as otherwise, the coils might burn in case of any spike or in case the gap between the coil and the magnet increases due to any reason. Voltage controllers should be used in most cases where the requirement is only to control the speed of the vibratory feeder and there is not much change in the input voltage or even the input frequency.
- Frequency Controllers – Voltage controllers vary the amplitude or the voltage while frequency controllers vary the amplitude / voltage as well as the frequency. The advantage of having a Frequency Controller is two fold. Firstly, in case there is a change in the input frequency, the speed / performance of the vibrator does not change. That means that even if you switch between generator power and that from the state board, there will be no change in the performance of the vibratory feeder. Secondly, with a frequency controller, one can change the “tune the vibrator”. That is the manual process of “tuning” of a vibrator which is increasing / decreasing the springs to ensure that the vibrator works well can be done by changing the frequency on the controller. This makes it very convenient in the long run if the performance of the vibrator springs deteriorate over time. These provide highly stable performance and can guarantee constant voltage and constant frequency to the vibrator unit. These are of tremendous value in case of intermittent usage of Genset. These also have the facility to change in output speed through a PLC, in case of requirement.
- Feedback Controllers – These have a sensor attached to the springs of the vibrator which provides feedback of the load in the vibratory feeder to the controller. The micro-chip in the controller takes this feedback and adjusts itself accordingly. This is of tremendous value in case of changing load and heavy components as also for automatically tuning the vibrator instead of tuning it by increasing / reducing the springs.
- Double Speedy – In case of double speedy, two potentiometers are given whereby one is used for course adjustment and one for fine adjustment. These are of use in case of weighting and batching systems.
- Constant Voltage – These controllers provide constant voltage and are useful in case of change in input voltage.
Elscint controllers are specially designed for controlling the amplitude of vibration in industrial electromagnetic vibrators.
The system is based on a integrated circuit which guarantees perfect synchronisation of the triac firing pulse with the waveform of the working voltage under all conditions.
Another thing to look for in a vibrator controller / regulator is whether it can operate at 50Hz or 60Hz. For more details visit – http://www.elscintautomation.com/products/vibrator-controllers-regulators/