Electric cash drawers don’t usually have a “constant” relay contact like mains switches — instead they open via a solenoid trigger contact from a POS/printer:

• The cash drawer contains a solenoid (an electromagnet) that pops the drawer open when power is applied briefly (a pulse), not continuously.
• This pulse is sent by the POS system or receipt printer through a small connector (often RJ11/RJ12 interface cable).
• Standard input voltages are around 12 V DC or 24 V DC — depending on model and region.
• The drawer’s connector cable usually has wires for:
  • Solenoid activation (to open)
  • Open/closed status switch (contacts) — a micro-switch inside that changes state when the drawer is open.

So “electric contact/constant” in this context means the electrical connection/signal that tells the drawer solenoid to trigger, and status contacts that tell the POS that the drawer is open or closed.

📊 Typical Wiring / Contacts in an Electric Cash Drawer

Most standard electric cash drawers use an RJ11/RJ12 interface cable with pins such as:

• Power/Solenoid input (e.g., +12 V/24 V) — applies a momentary voltage pulse to trigger the solenoid.
• Drawer status switch contacts — open/closed sensors that change contact state when the drawer moves.

The exact pin functions depend on the drawer model and cable wiring. For example, on some drawers:

• Pins for solenoid activation (to open)
• Pins that close together when the drawer is open (status signal)
• Pins that open when closed
  This allows the POS software to know whether the drawer is open or closed.

⚡ How It Works Electrically

1. POS software or printer sends “drawer kick” signal (a brief voltage pulse) to the drawer solenoid.
2. Solenoid energizes momentarily and mechanically releases the latch.
3. Drawer opens.
4. Inside the drawer, a micro-switch contact changes state so the system can detect “drawer open/closed.”