800-5530 SD-3 Signal Driver, 3 Aspect, Bi-Color LED

The Circuitron SD-3 is an electronic signal driver for model railroaders building layouts with single searchlight-style LED signals. It controls bi-color or tricolor signals and produces red, green, and amber aspects.

Key details

• Application: HO and N scale model railroad layouts
• Material: 2-inch by 3-inch printed circuit board
• Compatibility: Single searchlight-style, 2-lead or 3-lead, bi-color or tricolor LED signals
• Compatible signal brands: Oregon Rail Supply, Tomar, Sunrise Enterprises, ISS, and others
• Input: 10–18 volts AC or DC
• Control options: Single-pole, 3-position switch or automatic detection circuits such as Circuitron BD-1, BD-2, and BD-3
• Important detail: Two SD-3 units are required for double-head signals. The SD-3 does not drive 3-lamp signals; see the SD-1 for that application.

Signal control for layout builders

Bi-color LEDs use red and green chips to create an amber appearance, with hue adjustment available on the SD-3. Other detection circuits may also be used when they provide a logic-low ground or negative output.

Related information

For manufacturer information, visit Circuitron Electronics. For related layout components, browse Train Layout Construction.