23 September, 2010
Controllers / Regulators for Vibratory Feeders
There are various types of controllers / regulators which can be”tune used for controlling the speed of a vibratory bowl feeder. The foremost requirement in most cases is for a soft start electronic controller. The various types of controllers can be classified as follows –
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. Further there should be a soft start provision as also 1 to 2 different settings of soft starts (as one type of soft start cannot fit to all systems!). Elscint offers Model E3FC with a 3 Amp current rating and Model E5FC having 6 Amp current rating. These controllers have an overload cut-off provision as also settable soft start provision. The major disadvantage of voltage controllers is that the performance of a vibratory feeder changes in case there is a change in the input frequency (this happens in case there is a switch between generator power and that from the state board). This is because vibratory feeders work on the induction coils wherein even a small change in the input frequency has a huge effect on the output performance of the vibratory feeder.
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. In case of frequency controllers, there are analog as well as digital frequency controllers. Elscint_Fre_01 and Fre_02 – These are manual frequency controllers with two potentiometers, one for frequency and one for voltage. These provide highly stable performance and can guarantee constant voltage and constant frequency to the vibrator unit. These are available at very competitive prices. These are of tremendous value in case of intermittent usage of Genset. Elscint EFQ1 – This is a digital automatic tuning frequency controller which searches for the correct resonant frequency of the vibrator.
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.
Double Speedy – In all models, DOUBLE SPEEDY is available i.e. two Potentiometers are given whereby one is used for course adjustment and one for fine adjustment. These are of tremendous use in case of weighting and batching systems.
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.