New and Original Yaskawa AC Servo Motor Industrial Servo Motor 1500RMP SGMG20A2ABS

Measurements: Use cheap multi-meters to measure I and V. Note that electrostatic damage of the meters beyond repair is not unlikely. Don’t use expensive equipment for this. Always keep computers and electro-statically sensitive equipment far away.  You can measure the current directly by inserting a current meter directly in the HV circuit near its grounding point.  Alternatively, the voltage drop V on the current sensing resistor, R=10k, also reveals the current, I=V/R.  The current readings will fluctuate because of the choppy nature of the current. Make an estimate of the average current reading. Then, the electrical power Pel = I * 7.5kV.  If the motor is lifting a weight, determine the mechanical power, Pm=mg h/t. There, m is the mass of the lifted object, g=9.81m/s2 , h is the change in height of the lifted object, and t the elapsed time.  Calculate the overall efficiency factor, = Pm/ Pel.

Circuit: The HV circuit is shown in the sketch above. The main component is a negative-ion generator power supply. These come in varieties operated from low-voltage battery sources or from a standard 110V outlet. As the current produced by these supplies is tiny, the hazard level appears to be low if you don’t carry any medical electronics. The motor operates via sudden charge/discharge events of the panels on the rotor through sparks. The HV current to the motor is occurring in a sequence of sudden spikes that exceed the current rating of the HV supply. Therefore, the supply must be buffered with a HV-rated capacitor. Film or ceramics capacitors with a capacitance of order 1nF and a voltage rating higher than the supply voltage Left: Top (friction) bearing. Right: Bottom (needle) bearing. For clarity, the tipped axle has been lifted out of the conical surface that forms the lower part of the bearing. Page 6 work well. I have inserted a 1Mcurrent-limiting resistor to reduce the risk of damage to the HV supply. Further, a 10ksensing resistor is used to measure the current. Electrical connections can be soldered or be made using wire nuts. As a rule of thumb, keep a distance of one to two inches between wires and components that have a high-voltage potential difference. Also, in order to avoid unwanted charge loss, round off all edges of the HV-carrying parts, wire joints, etc.. Cover open wiring by plexiglass or another type of HV insulator. Make sure the HV circuit is grounded somewhere. Note that typical insulated household and hobby wire is not safe to touch at HV. If you use a 110V outlet as primary, exercise the usual caution when making the 110V connections and when operating the device.