The JeeLabs Shop

This is a quality clip-on current transformer, suitable for the Parasitic Mains Current Sense project, described in the extensive JeeLabs Weblog series as the Micro Power Snitch (MPS). The device is well insulated from the mains potential in the monitored cable (double as standard, or triple when optionally using nylon spiral wrap around that cable).

This device needs an external burden resistor when used as a conventional AC current measuring device. The MPS operates differently, using a near open circuit mode to harvest energy from the primary circuit. An integral voltage limiting zener diode back-to-back pair ensures safety, even if the connecting wires are accidentally left unconnected.

Ordering Options:

The 100A CT jacked kit includes a single CT with integral 100 mm cable, terminated with a standard 2.5mm audio jack. Fine for quick connect/disconnect when breadboarding (2.5 mm socket not provided). For more permanent installations, see below.

The 100A CT wired kit includes a single CT with integral 100 mm cable, terminated as a pair of wires, already prepared for inserting into a connector block. For more permanent installations, this variant is preferable for a long-term, hard wired connection to a logic PCB.

The current transformer specification and performance as a energy harvesting source is freely available.