Mod 300W AC dimmer to 500W - Page 1
Forum section: electronics / beginners

author: 3dBi
author_rank: Contributor
timestamp: July 12, 2020, 08:00:42 pm
content: BoughtStairville PAR56 Active 300Wand got a bit dissapointed in light output. So I got wondering maybe there is some mod I could do to put 500W 230V PAR56 bulb in it (originally 300W 230V PAR56) and not fry dimmer circuits. I traced schematic (look in attachments) in high voltage part, as it looks like a triac dimmer with some extra fancy mains filtering, did not see the point to trace controller part, as it is optically isolated by MOC3021 and as my tiny understanding of triac dimmers - it should not matter.So what should be changed to get extra +200W of power capability to existing circuit?

author: eblc1388
author_rank: Frequent Contributor
timestamp: July 13, 2020, 12:29:43 am
content: Quote from: 3dBi on July 12, 2020, 08:00:42 pmThe TRIAC BTA06 is rated for 6A so it can safely handle the increased current at 500W. However, its dissipation increased linearly with the increased load current. Therefore the additional heat must be conduct/radiated away or else the body temperature will increased, possibly resulting in failure.You can use a small fan for additional cooling or mount it on a bigger heatsink. The BTA06 has electrically isolated tab so no insulation washer is needed between it and the heatsink metal surface. However, I would also earth the heatsink for additional peace of mind.

author: themadhippy
author_rank: Super Contributor
timestamp: July 13, 2020, 01:15:42 am
content: Whilst the triac might be able to take the extra current are you certain the lamp can deal with the increased heat and your gels,especially dark colour will burn out a lot quicker.The other problem is finding anything apart from narrow beam in 500w is getting harder,the days of par cans are unfortunately numbered

author: 3dBi
author_rank: Contributor
timestamp: July 13, 2020, 09:10:41 am
content: I just use pair of these old-school type par56 cans without any gels to get that nice warm white light flooded across an area for band in small venues (weddings, parties etc) so gels is out of equation. I had a similar short par56 without any active electronics with 500W bulb and it was doing just fine. This is standard (long) one, so I think enclosure will be ok. Rest of lighting set consists of led lights.I will certainly do some comparative tests with a IR thermometer before deployment.I'm more concerned about those filter inductors, that vertical one in heatsrhink without any markings indicating value L1, balanced double inductor 30mH one L2-A L2-B and that NTC thermistor that is rated 2A max steady state current @ 25°C. Well thermistor just can be replaced with 3A one and done deal. What about inductors? Rest of capacitors and resistors it think is fine.

author: 3dBi
author_rank: Contributor
timestamp: August 12, 2020, 07:53:59 pm
content: Changed NTC to 3A, filter choke to same 30mH just 5A one. Changed inductor L1 to 1mH 3A torodial type. Circuit works with 500W lamp, but at 1-4% dimmer setting, lamp does not turn off, either stutters or stays full on. Again, my understanding of triacs is none. Googling up showed similar problem when optoisolated triac would not turn off, fix was putting on snubber. Maybe I have to change snubber R3 C3 values accordingly? Anyone have any knowledge of how this works?

author: nigelwright7557
author_rank: Frequent Contributor
timestamp: August 13, 2020, 12:14:34 am
content: hopefully the pcb tracks are thick enough for extra current.

author: 3dBi
author_rank: Contributor
timestamp: August 13, 2020, 12:50:03 pm
content: Pcb tracks are quite wide for high voltage side. Checked with thermometer, no heat there. Changing C3 to 100nF and R3 120R circuit works with original coil (L1). Coil gets quite warm, about +70°C. Too bad I don't know the value of said coil.