| TABLE OF CONTENTS |
|---|
| 1. | Unidirectional Valve Drivers | 2 |
| 2. | Bi-Directional Valve Drivers | 3 |
| 2.1 | Single Axis Controllers (SAC) | 3 |
| 2.2 | Solid State Propel (SSP) | 3 |
| 2.3 | Servo Board (SVC) | 3 |
| 3. | Valve Driver Options | 3-4 |
| 3.1 | Current Feedback | 3 |
| 3.2 | When to Use Current Feedback | 3 |
| 3.3 | Feedback | 3 |
| 3.4 | Overload Protection | 3-4 |
| 3.5 | Pilot Output | 4 |
| 3.6 | Relay/Dual Decode Input | 4 |
| 3.7 | Short Circuit Protection | 4 |
| 3.8 | Sourcing vs. Sinking Outputs | 4 |
| 3.9 | Two Wire Connections | 4 |
| 4. | Figures | |
| 4.1 | Figure 4: PWM Waveforms | 1 |
| 4.2 | Figure 5: Input Voltage Windows for HED Valve Drivers | 2 |
