Radio Design Labs STRG1
Ramp Generator

STRG1

The ST-RG1 is a digitally generated 0 to 10 volt Ramp Generator in the group of STICK-ON series products by Radio Design Labs. These products are designed for quick, convenient installation, and reliable operation in a variety of control applications.

The ST-RG1 provides many important features:

• Its 0 to 10 volt output is the ideal interface toremotely control voltage Controlled Amplifiers, such as RDLs popular ST-VCA2
• A single VCA may now be controlled from severallocations. Only a pair of buttons, (UP and DOWN), is required at each controllocation, or RDL's RLC2 Remote Level Contro2
• LED level indicator driver circuitry is included in the ST-RG1

The ST-RG1 provides terminals for connection of two momentary buttons; one to ramp up, the other to ramp down. This is usually accomplished with RDLs RLC2 Remote Level Control. When power is applied to the ST-RG1, the output terminal is at its lowest (0 volt) point. When the UP button is pushed, the output ramps upward. When the UP button is released, the output remains stable at the voltage present when the button was released. When the DOWN button is depressed, the output ramps downward as long as the button is held in. When the ST-RG1 output reaches either minimum or maximum, it remains there until the opposite button (or closure) is applied. If the remote button is pushed momentarily and not held in, the ramp will step 200 millivolts, nominal, in the selected direction.

Two LED outputs are provided. A red LED connects to the LOW output; a green connects to the HIGH output. When the ramp is fully on (10 volts), the green indicator is fully on, and the red is fully off. When the ramp is at minimum, the red is fully on and the green is fully off. The circuit is designed to vary the current to each LED in proportion to the relative position of the ramp. If the ramp is at 5 volts then both indicators are equally illuminated. With this system, only two LEDs are required for full visual level indication!

The ST-RG1 provides the ideal interface for audio volume control through RDLs ST-VCA2 voltage Controlled Amplifier. The ST-RG1 is a Ground-referenced product which may operate from the same power supply as the ST-VCA2. Any number of UP and DOWN buttons may be connected to the ST-RG1, allowing VCA control from multiple locations. The output drive current from the ST-RG1 is more than sufficient to drive two ST-VCA2s.

Specifications:

• Control Inputs (2): 1 to ramp UP, 1 to ramp DOWN
• Input Logic: External closure pulls normally low input to +15 Vdc to activate UP or DOWN function
• Indicator Outputs:
      * 1 to drive red LED partial tofully OFF
      * 1 to drive green LED partial to fully ON
• LED Output Current: 0 to 3 mA (to drive low current, high intensity LEDs)
• Ramp Output: 0 to 10 volts nominal, (typical less than 0.1 v to greater than 9.8 v under ST-VCA2 load)
• Minimum Step: 200 mV nominal
• Ramp Time: 5 seconds (fully off to fully on; or fully on to fully off)
• Power Requirement: 24 to 33 Vdc @ 40 mA, Ground-Referenced

Our Part #  STRG1