The potentiometer is the core of the electric control joysticks, and the angle sensor converts the displacement signal sent by the hand into an electric signal through the potentiometer. The potentiometer is the earliest electric control joystick sensing method. The advantage of the potentiometer is strong anti-interference ability and low power consumption.
Icon of potentiometer:
Potentiometer picture:
Three-terminal potentiometer and four-terminal potentiometer:
Common potentiometers are three-terminal potentiometers, as shown in the figure. The four-terminal potentiometer adds a neutral terminal to the three-terminal potentiometer, which is the characteristic of the commonly used potentiometer on the electric control handle. Generally, the electric control handle is in the center position when it is at rest, and it can slide back and forth or left and right.
Potentiometer used on the electric control joystick:
Generally, long-life conductive plastic potentiometers are used on electric control handles. The use of highly wear-resistant conductive plastic film, coupled with high wear-resistant rare alloy brushes, potentiometer life can reach more than two million times. Our company's HJ30 series products use customized long-life potentiometers. The HJ60 series products use a customized potentiometer composed of long-life resistors and rare alloy brushes.
Photo of Potentiometer for HJ30 series joystick:
Photo of resistors and brushes for HJ60 series joystick:
The characteristics of the potentiometer used in the electric control joystick:
Long life: Due to the particularity of industrial electronic control joysticks, almost all electronic control handles are required to have a repetitive operation life of more than 1 million times, and some applications need to reach more than 10 million times. The life span of ordinary carbon film potentiometers is only 100,000 times or less. Therefore, potentiometers made of special materials are used on electric control joysticks. We call them "long-life potentiometers" or "conductive plastic potentiometers". The current life of this kind of potentiometer can generally reach two million times. Potentiometers with a service life of up to 10 million times require special customization.
Small angle: The operating angle of the general electronic control joystick is between 40° and 60°. Therefore, the potentiometers used on the electric control joysticks are all specially customized.
Resistance value range: The total resistance is generally within the range of 2K; 5K; 10K.
Precautions for the application of potentiometer joysticks: Before using the handle, be sure to confirm the joystick manual before powering on. Once the wrong wire is connected, the potentiometer may be burnt. The reason is that if the sliding end of the potentiometer is connected to the power or ground, and then the handle is operated, when the potentiometer on the handle slides to the power or ground, the resistance value on the loop tends to zero. According to Ohm's law, the resistance in the loop The current tends to infinity, and the potentiometer will burn out, so special attention is needed. The solution to this problem is to try not to choose a potentiometer with a sliding range of 0%-100% when selecting the joysticks. It is best to use a potentiometer with a sliding range of 10%-90%, so that the potentiometer will not be burned even if the wrong wire is connected.
In addition, when designing an electronic control system, the potentiometer must be connected to the sliding potential mode (the left figure below), not the rheostat mode (the right figure below). In the sliding potential mode, the resistance value of the potentiometer does not affect the accuracy of the output signal; if connected to the rheostat mode, although the signal can be adjusted, it will affect the resistance value after a long time of use signal accuracy.
Examples of potentiometer joysticks:
FJ1 series joystick
FJ120 series joystick
FJ11series joystick
HJ30 series joystick
HJ60 series joystick
HJ18 series joystick
