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3. Safety and Compliance

The ΔStop 100 controls the relay unit, which switches the AC power delivered to your enlarger. The relay handles the same voltage and current that runs through any wall outlet in your darkroom. Treat both units with the same respect you would any piece of electrical equipment, and they will give you years of reliable service.

Please read this section before connecting the unit.

Electrical Safety

Use only the power supply included with your ΔStop. Substituting a different adapter can damage the unit and void the warranty.

Do not exceed the rated load on the relay unit's switched outlets. The relay is designed to switch standard darkroom enlargers, which typically draw well under the rated maximum. If you are unsure about your enlarger's power draw, check its specification plate or manual before connecting. Refer to Section 11 for the ΔStop's specific load rating.

Never open the enclosure while the unit is connected to power. There are no user-serviceable parts inside. If the unit needs service, contact support.

If the ΔStop, its power supply, or any connected cable shows signs of damage (fraying, cracks, scorching, unusual smells, or a loose connection) disconnect it from power immediately and do not use it until the issue is resolved.

Operating Environment

Darkrooms are humid places, and humidity is the most common environmental stress on darkroom electronics. The ΔStop is built to tolerate normal darkroom conditions, but a few practices will extend its life considerably.

Keep the unit away from direct contact with chemistry. A splash of fixer or developer on the faceplate should be wiped off promptly with a damp cloth followed by a dry one. Do not allow liquids to pool on or around the unit.

Position the ΔStop on the dry side of your darkroom whenever possible, away from trays and sinks. If your space does not permit this, consider a small shelf or riser to keep the unit above typical splash height.

Allow the unit to reach room temperature before powering it on if it has been moved from a cold environment. Condensation inside the enclosure can cause temporary issues or long-term damage.

Enlarger Compatibility

The ΔStop is compatible with most standard darkroom enlargers that use a switched mains lamp. This includes the majority of Durst, Beseler, Omega, LPL, Kaiser, Meopta, and similar models.

The ΔStop is not designed to control:

  • Enlargers with integrated electronic controllers that expect their own timing signal
  • LED enlargers or color heads that require low-voltage DC switching or specialized dimming
  • Cold light heads with dedicated power supplies that bypass the lamp switch