A portable long wave and short wave UV 4w lamp DESIGN IDEAS... - Page 1
Forum section: electronics / beginners

author: k.neo
author_rank: Newbie
timestamp: December 28, 2023, 03:07:15 am
content: Hello.I want to build a portable lamp using 2 tubes by USHIOF4T5BLB, 4.5W Blacklight Blue T8 Fluorescent Tube (29v 0.17a)G4T5 Ultraviolet UVC, 4W T5Going to use ZWB3 UV Coated Glass Band Pass Filters for removing visible light from the G4T5 tube, F4T5 comes with its own coating.Both tubes share very similar specs, difference is in wavelength, "long" wave and "short" UV wave.Power source would come from 3x 18650 cells, 3s, would probably need a bms circuit with 12v? output, protection and charging.The idea is to use the IR2153 halfbridge circuit, there is this circuit implemented by Danyk athttps://danyk.cz/zarivk_p_en.htmlAll credit to the original website.Since I dont know how to choose the choke and the capacitors I am asking for directions.There is this program called Ballast Designer v4 from 320volt that uses several IR ic's but the IR2153 is not an option.What mosfets would be suitable to light up the tubes safely.The idea is to power each tube individually or both at the same time. The tubes are to be placed side by side with a bypass filter covering the tubes.Use scenarios are varied, hunting for fluoresence outdoors, thin layer chromatography, stamps & banknotes detection.Meanwhile I will be dumpster diving for CFL's to harvest chokes.Please help.Thank you.

author: Andy Chee
author_rank: Super Contributor
timestamp: December 28, 2023, 03:34:55 am
content: It doesn't matter if Ballast Designer doesn't have the IR2153, just make sure the operating frequency is identical, then the ballast choke and tube capacitor components should be the same.For example, select IR2156 in Ballast designer, and take note of the operating frequency. Then look at the IR2153 datasheet to calculate the resistor capacitor values for the components on pin 2,3,4 for the same frequency.

author: CaptDon
author_rank: Super Contributor
timestamp: December 28, 2023, 11:44:03 pm
content: You do note that the power supply for that drawing is probably about 320VDC on the filter capacitor? How do you intend to get the lamps to work from a 12vdc source? I don't know where you got that 29 volts at .17 amps rating for the tubes but it is way the hell off. Those lamps won't even ionize below about 80 volts and that is after preheating the filaments. In the states those bulbs are supplied through a 4,6,8 watt ballast (Yes, I have seen the 4 watters being supplied by 8 watt ballasts in commercial products) from 120VAC 60Hz (the ballast is a simple two wire inductor) and the circuit may include a glow trigger starter (FS-5) or a manual push button. This needs a lot more thought. I have a little camping tent light that uses an F4T5CW cool white bulb and runs from 4 'C' cells for hours. I also have an F4T5BLB and the G4T5 germicidal lamp which I can swap into the unit for searching at night. I wonder if they make an F4T5BL unfiltered black light bulb similar to the F40T12BL bulbs?

author: thm_w
author_rank: Super Contributor
timestamp: December 29, 2023, 12:09:03 am
content: Quote from: k.neo on December 28, 2023, 03:07:15 amIMO germicidal UV bulb has no place in these use cases, is unnecessarily dangerous.F4T5BLB is rated as 350-365nm, I'm not sure of the lumen output, 200-400lm?You can consider purchasing 3W 365nm LEDs from seller HotRed on aliexpress. Or 10W 5050 LED, though some are mixed 365nm 395nm, so check first.

author: k.neo
author_rank: Newbie
timestamp: December 29, 2023, 05:30:30 pm
content: You are right about the AC power source, its uses a high voltage to strike the arc.I kind of ignored this untill now.Would the IR2153 work for DC power source?3S 18650s would work and have plenty of 10A bms ciruits.Or what ic is there that is more apropriate for a DC source.Here are some 8w unfiltered, white coated, UVa tubeshttps://es.aliexpress.com/i/32810121847.htmlMeanwhile I have ordered 3 of those 4w portable uv flashlights. To see how they power it.Its going to be a helluva cheap circuit there. I want to build one ballast with preheating.UVc is also needed, yes its a bit more dangerous, but using ozone free tubes and understanding the dangers and limitations one should always wear some uv blockers. After all UV is invisible and we only search for luminescence that is triggered by the uv light.The lamp would have a ZWB3 glass to filter out the visible portions of emmision and bypass the UV.

author: Andy Chee
author_rank: Super Contributor
timestamp: December 30, 2023, 03:31:31 am
content: Quote from: k.neo on December 29, 2023, 05:30:30 pmIR2153 will work ok from DC that is no problem.The problem is the tubes require high voltage AC and without a transformer, IR2153 can only convert DC to AC at same voltage e.g. 12VDC to 12VAC.You need to first convert 12VDC to about 200VDC. Then the IR2153 converts 200VDC to 200VAC for the tubes.Unfortunately the design by Danyk athttps://danyk.cz/zarivk_p_en.htmlis not designed for 12VDC operation. It will require several changes to make it work on 12VDC.Have a look at Ballast Designer IR2156, it has a 12VDC schematic that could be adapted to your requirements.QuoteCorrect. Most cheap fluorescent lamp torches will be along the lines of:https://web.archive.org/web/20080729070957/http://repairfaq.ece.drexel.edu/REPAIR/F_samschem.html#SAMSCHEM_011Code:o T1+ o----+----------+----------------+ o| | )|:| +--------------+-+| \ D 28T )|:|( | || R1 / #26 )|:|( +|-|+| 560 \ +---------+ |:|( | - || / | |:|( O 315T | | FL1| | | o |:|( #32 | | F4-T5| +------|---------+ |:|( | - || | | )|:|( +|-|++_|_ C1 | | F 28T )|:|( | |--- 47 uF | | #32 )|:| +--------------+-+- | 16 V | | +---+| | | Q1 | O = Output| | C \| | D = Drive| C2 _|_ |---+ F = Feedback| .022 uF --- E /| || | | _|_ C3| | | --- .022 uF| | | |o-----+----------+------+-----+

author: CaptDon
author_rank: Super Contributor
timestamp: December 30, 2023, 03:54:55 pm
content: I am not sure why, The 4 watt battery operated units seem to get good bulb life BUT any of the 8 watt battery / 12vdc powered units seem to kill the bulbs in short order. One end of the bulb seems to darken quickly from ion sputtering of the filament and cathode elements. The 4 watt units don't seem to show this malfunction?

author: k.neo
author_rank: Newbie
timestamp: December 30, 2023, 05:57:26 pm
content: Quote from: CaptDon on December 30, 2023, 03:54:55 pmI guess its a case of an insta starting ballast that just zaps the tube instead of taking 2 seconds to preheat the electrodes.The blackening is the metal leaving the electrodes because of getting too hot.Isnt is so?

author: CaptDon
author_rank: Super Contributor
timestamp: December 30, 2023, 06:04:29 pm
content: Most of the units don't supply any filament current as such. They supply a high frequency high voltage signal across the tube. Often the filament connections are paralleled on each end. I think they rely on the arc current to keep the cathodes warm. I think in mercury vapor devices if the cathodes run to cool or the mercury is condensed and not fully vaporized there is some sort of ion bombardment of the cathodes causing sputtering.

author: Andy Chee
author_rank: Super Contributor
timestamp: December 31, 2023, 02:06:12 am
content: Blackening is definitely due to the cold filament losing emission material, which is why preheating is the preferred way to ignite a tube.https://web.archive.org/web/20080110151142/http://members.misty.com/don/f-lamp.html#ioibeLow voltage battery inverters will often lack preheating, obviously to keep costs down (but sacrificing tube life in the process). Indeed normal operation may also be running the tube with less than ideal current, therefore the filaments are running dangerously cool.Blackening at only one end seems to suggest some sort of DC bias when the circuit starts up.

author: Terry Bites
author_rank: Super Contributor
timestamp: December 31, 2023, 02:36:39 pm
content: I'd get some ready mades, the sort of thing you get in an old fashioned camper fluouro fitting. Easy to fix, no exotic parts.eghttps://www.ebay.co.uk/itm/225608120941?hash=item34874aba6d:g:OCIAAMXQwKdRcmzh&amdata=enc%3AAQAIAAAA8KsL1EMmpUPX83NUtvyaPddORl%2BGswKnWmEeL9igoa9wbJc3D6hWC9g8LGRWA84VEBrIdtOaNLsF75qiIHrHSeaUjTScpFGt02matl7XLErB6AfcJ%2FFaIAwkufZnhZaH%2FjbZzfhyJA1IICS%2FMUXtUuLSSqI4Ooke6yzjWhj2A%2B7qwQEQ%2BWduCKlI%2FKDCPMYNLyj5SiXsLW9zH32S4OpBUXCukwN%2FPbm%2FP7DtA6Sl4TfbOIcdv4jvd2jDRfxQfPbnZUC1GwGrK5ApsJX9aGEGf6AjT%2FVM1j3bnAJtXLwmttm9DfOwjpR5kMTZaV6oJIeH9g%3D%3D%7Ctkp%3ABk9SR_7M44SYYw

author: k.neo
author_rank: Newbie
timestamp: January 01, 2024, 06:46:57 pm
content: Camper van looks like a legit solution but is it preheating?What about if I used a DC DC boost converter to raise 12v to 300v? and plug it in the circuit at the 1st post.Could that work?I kind of dig these electronic ballast controller with the warm starting features.

author: Zero999
author_rank: Super Contributor
timestamp: January 01, 2024, 07:20:17 pm
content: Quote from: thm_w on December 29, 2023, 12:09:03 amRegarding safety: UVC is dangerous but is still used for looking for rocks which contain phosphors. A germicidal tube is used, with a visible light filter and the person using it wears protective goggles and clothing.QuoteHopefully close to zero, since you want as little visible light as possible, since you want to be able to see the light emitted by fluorescence. Lumen only makes sense for visible light. UV is measured in radiometric power output.Quote from: k.neo on January 01, 2024, 06:46:57 pmFor the UVC lammp, use the circuit in the original post, but with the IR2153D run directly off the batteries and driving a small transformer, rather than an inductor.Use UV LEDs, rather than a fluorescent tube for UVA. It's much more efficient and easier to drive. A constant current output buck converter driving 2W of LEDs will produce as much UVA, as a 4W fluorescent lamp.

author: k.neo
author_rank: Newbie
timestamp: January 02, 2024, 09:45:54 pm
content: I was thinking about going cold cathode 254nm lights, they do come in 5v powered variant. And if the 365nm is provided by leds it would be nice, but imho the black light uv tubes do offer a better spectral range that peaks in the 365nm region even insects are attracted to tube UV-a rather than leds.I did some lurking in infineon suport forums and there actually is a dedicated uv ballast ic, its the icb2fl03ghttps://www.infineon.com/cms/en/product/power/lighting-ics/fluorescent-ballast-ics/icb2fl03g/Someone asked about same topic (4w dc ballast) and the reply was:Code:We have only one Ballast IC which is ICB2FL03G. However, its max. voltage Vcc is only 18V.For other LED drivers, we have TLD5542-1 which can support 24V input voltage, but only 55V output maximum.TLD6098-1EP supports also 24V input voltage, but a higher frequency.