Hero999
Banned
Most of use have heard of the Joul thief but did you know that ferrite beads make handy core for pulse transformers?
Take a ferrite bead.
Wind 10 turns of 0.125mm of enamelled wire for the primary.
Wind 3 turns of megathin PVC insulated hook-up wire for the secondary.
Don't use enamelled wire for both of the windings because the insulation won't be good enough for mains isolation. Most PVC wire can stand 2kV for short periods of time and enamelled wire can't.
I've tried using one turn for the primary and one for the secondary but it took 532mA on the secondary to trigger the triac. With 10 on the primary and 3 on the secondary it would trigger at 10mA.
This simple technique removes the need to buy big and bulky overpriced pulse transformers or opto-triacs.
Take a ferrite bead.
Wind 10 turns of 0.125mm of enamelled wire for the primary.
Wind 3 turns of megathin PVC insulated hook-up wire for the secondary.
Don't use enamelled wire for both of the windings because the insulation won't be good enough for mains isolation. Most PVC wire can stand 2kV for short periods of time and enamelled wire can't.
I've tried using one turn for the primary and one for the secondary but it took 532mA on the secondary to trigger the triac. With 10 on the primary and 3 on the secondary it would trigger at 10mA.
This simple technique removes the need to buy big and bulky overpriced pulse transformers or opto-triacs.