We are moving in late 2020 and are currently only selling 3D printed items.

We will resume normal business after our move.

Manuals, application notes, and firmware updates are on the Support page.

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Please contact us for 3D printing services.

4201-B, stellarDMX DMX512-A Controller

This is also sold by Hammarö ljud in the EU.

A converter/controller that controls up to 512 channels of dimmers, moving lights, Christmas lights, etc. Used by theatres, museums, TV/movie studios, conference centers, home automation, architectural models, sculpture lighting, bands, clubs, etc.

Smooth fades on 1-512 channels, host controlled (works with architectural controllers, Windows, OS X, Linux, architectural controllers, and many other computers), MIDI controlled, and stand-alone (host computer only needed for initial setup) modes. A Grand Master Fader allows control of all channels at once.

Up to 127 presets or looks may be stored internally and called up by command from a host computer or MIDI controller, by time, or by external event (eight 0-5V analog inputs, 5 can be alternately used as digital/switch inputs). Cross fades may be done on a group of channels or all channels at once. A macro language allows small programs to be stored internally and executed on command and/or automatically on power up.

Eight external inputs (any mix of 0-5V analog, potentiometer, logic level, contact closure) allow interfacing to many other systems or even just a bank of potentiometers/sliders. User controllable LED (on, off, and two blink rates) to assist in debugging installations.

In host controlled mode, any computer or architectural panel with an RS-232 port or a USB port (Windows, OS X, Linux) can send detailed changes on a channel by channel basis, perform cross fades on some or all channels, and load/execute macros. Special commands are included to make use with architectural controllers and inexpensive dimmers easier.

In MIDI controlled mode any standard MIDI control device may send detailed changes and/or perform cross fades and also operate the Grand Master Fader. MIDI mode may be set to automatically start at power up. A host computer is required to initially set up the 4201-B but is not required after that.

In stand-alone mode a single preset or look is loaded at power on and an optional macro will then automatically start (as long as MIDI auto-start has not be set up). The macro can read the analog/digital inputs and make changes based on those as well as an internal time clock. Macros can also communicate over the USB and RS-232 ports, you could even control a second device from this one.

Fits in tight spaces, only 4” x 6” x 1” (102mm x 153mm x 25mm) with wall mounting ears on each side. Runs on 5-48VDC or can be powered from the USB port. Made in USA, meets the ANSI E1-11-2004, DMX512-A specification and FCC emissions standards. Transitioning to RoHS, specify at time of order if you need a RoHS unit (both stocked).

Free stellarConsole 24-channel control program for Windows, OS X, and Linux and open source demonstration programs are available from our Support page.



The SmartLight™ Theater Lighting Software from Edgeview Software LLC does not support the “B” version and has been discontinued.

MIDI to RS-232 Adapter

This adapter was designed specifically for use with the 4201-B above. It allows connection of the 4201-B to any standard MIDI controller.

Powered by the 4201-B through the RS-232 port, this adapter does not require any external power and does not draw any power from the MIDI controller. Some USB ports will not be able to power both the 4201-B and the MIDI adapter at the same time so it is suggested to use an external power supply such as an AC adapter for the 4201-B whenever the MIDI adapter is connected.

Activity LED indicates the presence of MIDI data.

The IN cable is optically isolated, about 5½ feet (1.6m) long and has a MALE DIN connector so it may plug directly into the MIDI device controlling it.

The THRU cable is about 6 inches (15cm) long and has a FEMALE DIN connector. The THRU cable shares power and ground connections with the 4201-B so care should be taken to avoid ground loops. Also, some MIDI-powered devices may draw more current than is available from this adapter. Any MIDI device that has another power source should work just fine.

The instructions for the use of this adapter are included in the 4201-B User Manual, version 2.10 and later.

If you wish to use this with an RS-232 device other than the 4201-B, please contact us for compatibility and setup information. There may be some RS-232 devices that can damage this adapter.

Made in USA, RoHS

Rotator – DMX512-A/Stand-Alone Rotator

The DMX512-A Rotator is intended for rotating mirror balls, signs, and other lightweight items under the control of a DMX512-A master. It can also operate in stand-alone mode where it accelerates to a user selected speed and maintains that as long as power is supplied. Main applications are live theater and retail/trade show displays.


There are two speed ranges, 0 to 2.55 rpm and 0 to 25.5 rpm. Any time the speed is changed, the Rotator automatically accelerates/decelerates the load to make smooth transitions and to prevent overloading the motor.

Under DMX control you may set change the speed, direction, and motor power at any time. The motor power in stand-alone mode is preset.

Requires 12 VDC at 1 Amp from either a standard AC adapter or it can optionally be powered from pins 4 & 5 of the DMX512 connection.

Click here for instruction manual.

Click here for a short video of the prototype being tested.

NOT FOR OVERHEAD LIFTING
MAXIMUM WORKING LOAD IS 10 kg

The definition of “overhead lifting” varies, check with a qualified rigger and/or your Authority Having Jurisdiction to determine if this may be used in your application.

Sequencer_8CH – Eight Channel Sequencer/Flasher

A very small (1.7” x 3.8”, 43mm x 96.5mm) low voltage DC controller with eight independent outputs/channels. Fully programmable sequence and timing with 1mS (0.001 second) resolution.

Each output can switch 250mA (400mA peak) at up to 24V. For higher currents and AC control the outputs can drive solid state relay or mechanical relays (see our order page for solid state relays or contact us to special order almost any relay you might need).

The stepping speed can be adjusted live using a potentiometer on the board or through the RS-232 interface. It can also be locked to 100% or a specific value from 1% to 255%.

Programming is simple using either a text editor or a spread sheet program such as LibreOffice Calc. Single stepping, program edits, nested loops, and debugging features are included. Two switch inputs for optional program control such as a START button in a museum display.

This controller should be mounted in an enclosure (not included) and is sized to fit perfectly in a standard USA electrical box with a blank cover. It is designed for use in up to 70C (158F) environments so is ideal for outdoor and industrial use with appropriate enclosure.

RS-232 host control for setup and/or remote control. Includes RS-232 cable and adjusting screwdriver.

Made in USA, RoHS. An Extra Low Voltage (9-24VDC) product.

DC Dimmer 4CH – Four Channel DMX512 Dimmer, Version 2

A very small (1.7” x 3.8”, 43mm x 96.5mm) low voltage DC dimmer with four independent outputs/channels. Works with halogen and LED lights and non-dim applications such as driving small DC motors and relays. One DMX512-A input with switchable termination and programmable channel number. Screw terminals for all connections.

Each output can switch up to 10 Amps at 48VDC. The entire board is limited to 20A continuous, this can be divided up any way you wish between the four channels as long as no channel exceeds 10A continuous and 40A peak (for halogen lamps cold start).

This dimmer should be mounted in an enclosure (not included) and is sized to fit perfectly in a standard USA electrical box with a blank cover.

Uses PWM dimming with staggered start times to lower EMI and ease the load on the power supply. Made in USA, RoHS.

New in this version:

  • Isolated and Protected DMX512 input

  • 8 and 16-bit dimming

  • Higher PWM frequency for less flicker

Available on special order:

  • Connector for remote LEDs

  • ModBus control

  • RS-485 text control

  • Pre-programmed sequences with trigger input

  • Dedicated stepping motor control

  • Mounted in an enclosure with or without power supplies

  • Custom firmware/hardware for your specific needs

Switch-4 Four Channel Switch Input

Switch-4X Extended version

A small device that reads up to four switch inputs (contact closures or logic level inputs) and sends commands to a computer or MIDI device. MIDI and RS-232 versions available, other versions coming. Custom data strings and full custom versions are available.

A typical use would be for START buttons in a kiosk, museum display, etc. for video, audio, light, motion, or other automated displays. The inputs can be almost any type of switch or sensor (light, motion, temperature, etc.).

MIDI standard data is sent as simple Note ON and OFF commands. RS-232 standard data is a letter followed by a carriage return (A-D, upper case = ON and lower case = OFF).

The Switch-4X extended version allows you to load in any MIDI or RS-232 data you wish (see the manual on the Support page for limitations). RS-232 baud rate, debounce time, and data polarity are also customizable. The Switch-4X requires an interface cable and our free setup utility to create the programming.

A Status LED indicates the device is normally on and blinks for any changes on the input.

3.5” (89mm) W x 2.5” (64mm) H x 1” (25mm) T with mounting flanges. Requires 9-24VDC power. Made in USA, RoHS.

DC Dimmer – Four Channel DMX512 Dimmer, original version

A very small (1.5” x 2.5”, 38mm x 64mm) low voltage DC dimmer with four independent outputs/channels. Works with halogen and LED lights and non-dim applications such as driving small DC motors and relays. One DMX512-A input with switchable termination and programmable channel number. Screw terminals for all connections.

Each output can switch up to 40VDC. The entire board is limited to 20A continuous, this can be divided up any way you wish between the four channels as long as no channel exceeds 10A continuous and 40A peak (for halogen lamps cold start).

This dimmer should be mounted in an enclosure (not included). It may be optionally ordered mounted to a single or multiple gang wall plate (shown to the right) or in other custom configurations. Inquire for pricing on custom configurations.

Uses PWM dimmer with staggered start times to lower EMI and ease the load on the power supply. Made in USA, not RoHS.

HHIS-1CH, Hand Held Ignition System (Obsolete item)

A simple to use capacitor discharge firing system for fireworks, rockets, and special effects with extra safety features, a pyro-safe ohmmeter, and even a built-in white LED flashlight.

Options available at time of order include a digital password and/or a removable key. The password allows use of the ohmmeter while disabling arming and firing. The removable key removes power from the entire pyro section but the built-in flashlight will continue to operate. The key is a simple pin-type as used on other firing systems.

Complies with RoHS, NFPA 1123 (even without the key), and FCC emissions standards. Made in USA, not RoHS.

Optional key not shown in picture.

Product flier for HHIS-1CH

Custom Lighting Controllers

The 4201-B stellarDMX DMX512-A Controller was designed to be easily modified for custom uses and is also available as a bare or assembled/tested board for OEM use. We would be happy to quote on custom firmware and/or hardware.

Other Custom Products

We have been designing custom products for other companies since 1981.

Examples: computer audio boards (we helped start the computer sound industry), medical equipment used in several countries, Digital TV (DTV) products, telecom and industrial test equipment, modems (wired and wireless), motherboards, carnival equipment (some in constant use since 1993), aerospace, laser control and graphics systems, industrial control, consumer games, inkjet and laser printer controls, VoIP and many others.

Please feel free to contact us to see how we may help with your next project.



Durand Interstellar, Inc.
219 Oak Wood Way Los Gatos, California 95032-2523 USA
Ph: +1 408 356-3886
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