Building Your Electronic Gadgets

TESS LED Bulb Tear-down

This is a breakdown of the FIRSTGreen e-watt saver LED bulb. You can find more information about it here . This bulb is manufactured by TESS and retails for approximately $20.00.

Some of my testing revealed the following:

  • Voltage across the LED emitter is 23 volts.
  • Current is .23 Amps.
  • The temperature of the heat sink goes up to a toasty 67° C (152° F).
  • An incandescent and CFL bulb emits light in a rough hemisphere away from the socket while the LED bulb emits more light in the direction away from the socket.
  • When mounted on the ceiling, the LED bulb casts a darker shadow than a 100-watt bulb.


(You can click on any of the pictures to see a larger view.)

Tess LED Components

  • Complete bulb
  • Plastic diffuser
  • LED emitter assembly
  • LED retaining screws
  • Heat conducting rubber pad
  • Aluminum heat sink
  • Black plastic insulating sheets protect electronics inside the heatsink
  • Electronics printed circuit board and E-26 (medium or standard Edison) socket

The PCB fits mostly into the hollow socket.

Tess LED Emitter
This is a thick aluminum plate which mounts seven CREE LEDs.

Some LED Bulb Sources

  Posted: 2011.08.08