The Ultra Motion Power Supply Unit is an unregulated AC to DC supply designed specifically for DC motion control applications, including ServoCylinder, and is perfectly suited to most 36V DC motor applications. A Power Supply Unit (PSU) used in DC motion control applications must be sufficiently robust to provide the large bursts of current typical of motor acceleration, while also being capable of tolerating large voltage spikes generated by the motor during deceleration.
In DC motor applications, unregulated DC power supplies tend to greatly outperform the more common switching-type regulated supplies. Unregulated supplies have large capacitors which allow for large transient current draws and help to absorb voltage spikes. Furthermore, they are not subject to the large overshoots and undershoots characteristic of a voltage controller, which have a detrimental impact on motor performance, and potentially destructive impact on motor controller hardware, motor windings, and other equipment attached to the same power bus.
The Ultra Motion PSU utilizes a high-efficiency toroidal AC transformer, high performance rectifiers, and a large aluminum electrolytic capacitor. It also has a fully enclosed extruded aluminum housing which provides dust protection while also allowing adequate cooling. Furthermore, it has a fully integrated Over-Voltage Protection (OVP) device (similar to the Ultra Motion Power Shunt) which protects the bus from excessive voltage spikes due to both deceleration and Loss of Power (LoP) scenarios.
|Model||Ultra Motion 180W PSU||Ultra Motion 360W PSU|
|Maximum Continuous Load (@72°F)||5.92A (About 180W)||11.75A (About 360W)|
|Well Suited for…||1x ServoCylinder (Typical Applications)||1x ServoCylinder (Hi-Power Applications)
or 2x ServoCylinders (Typical Applications)
Layout of Ultra Motion Power Supply
- Power Switch (Lighted)
- Line-in Connector (C13 line)
- AC Fuse Holder
- DC Fuse Holder
- Power Output Indicator Light
- Over-Voltage Protection (OVP) Active
- EPO Out
- EPO In
- Positive (Red)
- Negative (Black)
- Ground (Earth/Chassis)
- Rail for #10 Square Nut
- Type: Unregulated AC to DC Power Supply
- Input: 100-125VAC, 50-60Hz
- 36VDC Unloaded, TYP
- 30VDC Maximum Continuous Load, TYP
- Fully integrated Over-Voltage Protection (OVP) device
- Emergency Power Off (EPO) ready
- High efficiency (over 80% at 10-100% of max continuous load), Quiescent power <5 watts.
- Regenerative, recaptures energy generated by deceleration
- 100% RoHS Compliant
- Dust-Resistant (IP50)
- Fused AC Input (5mm x 20mm Fuse, 250V, slow-blow, 6.3A)
- Fused DC Output (¼” x 1-¼” Fuse, 250V, slow-blow, application-dependent current rating)
- Temperature ranges:
- Operating: -10°C to +65°C (+14°F to 150°F)
- Storage (Non-operating): -55°C to +85°C (+67°F to 185°F)
Integrated Over-Voltage Protection (OVP) device
The PSU contains the same proven technology used in our standalone OVP device, the Ultra Motion Power Shunt. It is specifically designed to safely dissipate any potentially damaging voltage spikes generated by the system, such those that can occur when motors are rapidly decelerating, or from release of energy in Loss of Power (LoP) scenarios.
The system senses bus voltage, activating when the voltage exceeds a pre-programed value of 41.6V. It then drains excessive voltage to ground over a high-power shunt resistor until bus voltage is reduced to 37.5V before deactivating.
Theory of Operation
|TVS||Suppresses ESD, lightning, and other high-speed, high-voltage transients|
|Rectifier||Render the OVP device bipolar. The shunt will activate when |Vin| > Vact|
|Voltage Sense||Continuously compares the bus voltage with a pre-configured Vact voltage. When |Vin| > Vact , this circuit will switch the POWER MOSFET. The circuit features a hysteresis band of ~4V.|
|Power MOSFET||Once activated, allows the system to rapidly drain power from the main bus through the Shunt Resistor. The MOSFET has been sized to support a maximum continuous current of 72A.|
|Shunt Resistor||Dissipates the undesired bus energy into heat. Resistor is designed for high pulse energy to allow dissipation of a large amount of energy in a single burst.|
OVP Application Example: Rapid Deceleration under Load
Figure 14: In this application, an Ultra Motion ServoCylinder with a BLDC Motor is rapidly decelerating an 80 lbm mass. The bus voltage (yellow) rapidly rises at the beginning of the period of rapid deceleration until it hits Vact = 29V and then quickly drops when the shunt is activated. The shunt activation periods are indicated by high MOSFET voltage (green). The OVP device in the Ultra Motion PSU triggers at 41.6V, and deactivates at 37.5V.
Power Output Capacity
The limiting factor controlling the maximum continuous output power is the temperature rating of the transformer windings, which are NEMA Class B. We generally recommend preventing the top surface temperature of the PSU from exceeding 150°F (65.5°C). Under ordinary conditions (ambient temperature ~72°F, placement on non-conductive wooden surface, minimal forced convection) we find that this usually corresponds to transformer core temperature of about 250°F (121°C).
The supply is designed to allow short duty-cycle bursts of power, so the transformer has a very large thermal mass and will take several hours at maximum continuous power output to reach maximum steady state temperature. Figure 4 below depicts temperatures of various PSU components when subjected to the max continuous load and ordinary conditions.
It is possible to improve the life of the PSU and/or allow for larger sustained loads by improving the cooling conditions beyond what we define as ordinary conditions. You can heat sink the base of the PSU to draw heat, or improve air flow in order to aid heat convection.
Geometry of all PSU Models
|Model||Part Number||Case Length (“L”)||Bottom Hole Spacing (“S”)|
|Ultra Motion 180W PSU||PS-1X0A||10in||8.195in|
|Ultra Motion 360W PSU||PS-1X2A||12in||10.195in|
(A) Surface placement with rubber feet, (B) Bottom Mount, (C) Bracket mount, and (D) Side Mount
The power supply ships with 4x rubber feet perfect for placement on most horizontal surfaces with minimal vibration.
After removing rubber feet, 4x #6-32 UNC blind nuts become available. Take care to install screws to a depth not exceeding .345in from bottom surface.
Recommended: 4x Screws
Useful if opposite panel side is inaccessible, the PSU Mounting Bracket (P/N: 15399) has an adjustable position, and a .02in (#10) x .38in mounting slot.
Recommended: 4x Brackets
The side of the case features a #10 T-rail, which accepts a standard #10 square nut and allows screw installation to a maximum depth of .294 from the side surface.
Recommended: 2x Screws Minimum