Reversing Key Commutator For Lab
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Product Code : SCL-EAE-12119
Reversing Key Commutator For Lab (SKU SCL-EAE-12119) is a lever-operated switch that reverses the direction of current through a circuit without any rewiring. It is used in electromagnetism practicals in Class 12 and B.Sc. physics, for example to take deflections on both sides of zero with a tangent galvanometer. The commutator is manufactured by Science Lab Supplies at Plot 448, HSIIDC Industrial Area, Saha, Ambala, India, which sells it directly to schools, colleges, tender contractors and distributors.
Specifications
Every specification is listed separately in the table below. In short, brass contact elements are mounted on a high-density polymer base in a double-pole double-throw or four-way cross arrangement, with a central neutral position, an insulated lever knob and four 4 mm brass binding posts, rated at 24 V and 3 A.
| Specification | Value |
|---|---|
| SKU | SCL-EAE-12119 |
| Contact form | DPDT action or 4-way cross-commutator |
| Contact elements | Brass rods and contact strips |
| Base | High-density insulating polymer |
| Operation | Lever with non-conductive knob |
| Neutral position | Central open position isolating the circuit |
| Terminals | 4 x 4 mm brass binding posts (2 input, 2 output) |
| Maximum voltage | 24 V DC / AC |
| Maximum current | 3 A |
| Documentation | Configuration leaflet with wiring diagrams |
| Manufacturer | Science Lab Supplies, Saha, Ambala, Haryana |
| Country of origin | India |
Applications and Experiments for the Reversing Key Commutator
The supply goes to the input posts and the coil or meter to the output posts; moving the lever from one side to the other through the neutral position flips the current direction. Averaging readings taken in both directions cancels small alignment errors, a common requirement in electricity and magnetism practicals.
- Class 12 and B.Sc. physics: reversing current in the Tangent Galvanometer to average left and right deflections.
- Determining galvanometer constants from alternate-direction deflections.
- Electromagnetism and Lenz's law demonstrations with Induction Coils with Cores.
- Field-direction studies with Helmholtz coils and deflection magnetometers, fed from a source such as the Power Supply Unit/ Block for DC.
Always pause in the neutral position before reversing, and never exceed 3 A or use the commutator on mains supplies.
Standard Scope of Supply
The commutator is supplied as one Reversing Key Commutator For Lab unit with its binding posts, plus a technical configuration leaflet with wiring diagrams. Power supplies, coils, galvanometers and connecting leads are separate items that can be listed on the same quotation.
Packing, MOQ and Lead Time
Ask for one commutator for a demonstration or a quantity matching the number of magnetism benches in your lab. The resulting quotation spells out packing, delivery time and price for that quantity, and keys, galvanometers or rheostats for the same practicals can be added.
Science Lab Supplies is an IEC holder and can ship to buyers in Peru, Egypt, Iraq, Nigeria, Kenya and Ghana. Reach the sales desk through the contact page, collect products in the enquiry cart, or consult the lab tender page for institutional bids.
Frequently Asked Questions
Why reverse the current instead of swapping wires?
Reversing with a commutator is quicker, avoids loose or mis-connected leads, and keeps the rest of the circuit untouched, so readings in the two directions are taken under the same conditions and can be averaged reliably.
What are the voltage and current limits?
The commutator is rated at 24 V and 3 A for low-voltage educational circuits. It must never be connected to high-voltage mains, and the lever should rest in neutral before each reversal to avoid arcing.
How is it wired?
Connect the supply to the two input binding posts and the coil, galvanometer or magnetometer to the two output posts. Moving the lever left gives one current direction; moving it right through neutral gives the opposite.
Is Science Lab Supplies the manufacturer or a trader?
Science Lab Supplies builds the commutator in-house at its Saha, Ambala factory in India, so it is the manufacturer. Your quotation comes from the same factory that assembles and dispatches the switch.
Related Keys, Meters and Circuit Apparatus
These products work in the same circuits as the commutator: other plug and tapping keys for making, routing or reversing current, galvanometers and ammeters to read it, and a rheostat to set it. They come from the Electrical and Electronics and Lab Meters ranges and can be ordered together.
- Brass Four Way Plug Key — plug-type alternative that also reverses current, rated up to 5 A.
- Tapping Key Physics Lab — momentary key for brief pulses, 24 V DC and 2 A.
- Brass Two Way Plug Key Switch — routes current to one of two circuit branches.
- Brass One Way Plug Key — simple brass key to make or break a circuit.
- Ballistic Galvanometer — mirror-coil galvanometer for very low current measurement.
- Rheostat, Constantine (Eureka) Wire — variable resistance or potential divider with a sliding contact.
- Ammeter — DC meter on a bakelite or acrylic stand with lock-type terminals.
Browse the full Electrical and Electronics range, the Lab Meters range for galvanometers, or all physics lab equipment.
Last updated: 9 October 2026
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