Unresolved issue related to power-in

[Benny7440]

A niece of mine bought two mosqitoes zapper more than a year ago & gave one of these to her mother. My sister gave me that unit about 4-6 months ago because it never worked for her. Have no idea if my niece's still exists or someday worked for her.

The thing is that I openned it to see what was inside and it's pretty simple, but the power plug makes me believe it's a unit intended to work in other countries where you have receptacles giving off 220 volts, not 110 volts like in Puerto Rico.

Tried to make a diagram of the circuit but it proved harder than expected; it also has not a single character nowhere that can give me a clue, not even the bulb.

I suspect it involves a voltage doubler (starting with 220 V) because I injected 110 V and measured at the screen ~375 V, which is not enough for a mosqitoe even if it's physically
disabled.

Thanks for any help on this. See attached photo.

 

[73's de Edd]

Sir Benny7440 . . . . .

I agree 100% . . . . ..that is being a 220 VAC powered unit . . . . if you go by the plug on it.
To work with 110 line voltage would involve adding enough diodes and poly caps . . .like the two smaller ones and diodes to change it to a voltage quadrupler. Then you would just have to see how /if the fluorescent lamp worked, but the high voltage ZAPPO voltage should then be up to normal .
On your spiral HV grid, confirm for me that the very outermost winding is being ground and that the wire just beside it, is going towards the center of the PCB and connects to a current limiting resistor before it attaches to the HV which should be from the LARGE reddish brown poly capacitor.

73's de Edd
.....

 

[Benny7440]

With the purpose of adding to it another stage for doubling the voltage to the grid was that I tried to make a diagram first but after several trials found it difficult to understand and went to some sites in relation to voltage multipliers but never found a way to re-arrange my diagrams to agree with the different ways they're established. So, I even thought of building a quadrupler from the beginning and insert it there instead of the existing one. Have not decided which way to go, yet.

I'm attaching a couple of photos of the two sides of the board for your inspection. I'm not sure how to attach one of my diagrams other than taking photo of a page where I've drawn it but I'm sure there're some sites that let you draw and take a screenshot or download a copy of it (maybe a .pdf). Can you give me advise as to what's preferred?

I confirmed that the two outer wires (bottom & top) are the same but it's difficult to say if it's ground or not; in fact, that wire is connected to both diodes.

Thanks for replying, 73's de Edd!

 

[73's de Edd]

Sir Benny7440. . . . . .

Ohhhhhhhhh-tay . . . . . . . lets now see how much of this photo, that I was able to correctly make out from its blurriness, with you feeding back initial corrections needed to be made.
The end result, being a wiring schematic of the unit and then the use of flying wire construction to add on and then upgrade to a voltage quadruple circuit , with but use of a few more caps, resistors and diodes.

The alphabetic indicators relate to the distinct foil pads on the PCB with a few of the expansive ones receiving an additional like prime indicator suffix.
The numerical number assignments relate to external connections made into the PCB.

• Starting with the AC line power input, there is the 1 "hot" wire which comes in from the AC plugs narrow blade and folds around the end of te PCB and then solders into foil pad A.

• Then there is the companion AC line power input 2 " neutral " wire which comes in from the AC plugs wide blade and folds around the end of te PCB and then solders into foil pad B.

• Then there are the two RED wires from the central bug attractor florescent lamp with the cold lead 3 going to foil pad B and the hot lead 4 going to foil pad C.

• Then you need to help on the originating source of the 5 GREY wire, which connects into foil pad E prime.

The surrounding ?' marks relate to what probably are patterns in your floor tile, but could pass for wires to my restricted point of view.

• 6 appears to be the cold potential side of the paired set of wires that parallel up supports to fabricate the HV shock grid. ***

• Smaller capacitor 7 seems to connect to foil pads A and C as the square PINK pads.

• The companion small poly cap seems to possibly connect to the square BLUE pads.

• The largest poly cap seems to connect between E prime and F prime foil pads at the ORANGE squares

*** It appears that one of the nearby ? wires might also terminate into F prime pad.
If so that might have the spiral gridwork starting with an outer wire and then a center wire like 5? and then
a third wire then being also connected into pad F prime. Check me out on that ?

Correct me and feed back the other component connections into the assigned pad designators.

RELEVANT PHOTO MARK -UP . . . . .

73's de Edd
.....

 

[Benny7440]

In relation to wire 5 it is one of the two grid wires and is the inner one. I suspect that when you refer to the AC input wires above you're referring to a future scheme and not to the actual one because it's probably intended for 220 VAC, so there's no neutral, both are alive and kicking!
The ? are indeed part of the floor. The 2 ? to the right of 2 are the twisted cables from the cap and the other grid cable.

On cap 7 you're right. In relation to the big cap you're right, too. Your reference to wire 5 isn't correct because those are twisted wires from the cap and grid.

I'm going to check my camera settings and if I can augment its precission will upload better photos of both sides of the panel. Thanks for your help on this!

 

[73's de Edd]

Sir Benny7440 . . . . . .

It was assumed that the Euro connector AC plug was replaced with a proper 120VAC polarized plug.

Looks like only a last little bit of info now needs to be fed back, in order to then generate a schematic.

Please now inspect and confirm . . .

Board foil connection B's RED wire 3 goes to the top ? / bottom ? connector of bug lamp.

Board foil connection C's Red wire 4 goes to the top ? / bottom ? connector of bug lamp.

Board foil connection E- prime ends GRAY 5 wire goes to ? ( center wire of the spiral wound
electrocution grid with its grid wire being in the center and either wire to its side is being conneted to the
board foil terminal F's 6 and 8 wires. )

The above statement is dependent on the drawings now cluster of 3 ? marks on the far left as being patterns of the floor tile with the 5 wire being the only wire.
With the cluster of 3 ? marks to the far right of the schematic having the far two right ? marks as being tile patterns and the left ? mark is being a white wire just like the 6 wire and is now receiving its wire assignment identifier of 8.
The 7 and 8 wires then go to the grid network to be the wires to either side of a central 5 connected wire. The wires then make a circular wound, rising vertical spiral.

Then ascertain by inspection that . . . .

There is one carbon resistor of ? 1596 ? ohms connected between connections ?A? and ?D?.

There is one carbon resistor of ? 2468 ? ohms connected between connections ? E? and ?F?.

There is one vertically mounted 1N4007 diode connected between connections ?A? and ?E?.
with its cathode / banded end at ?E?

There is another vertically mounted 1N4007 diode connected between connections ?A? and ?C?.
with its cathode / banded end at ?A?.

There is one carbon resistor of ? 9999 ? ohms connected between connections ? E? and ?F?.

There is one carbon resistor of ? 1234 ? ohms connected between connections ? B? and ?D?.

Additionally . . . . .

The value of poly capacitor 7 between connections ? A? and ?C?.
is ? 0.1 ufd @ 630VDC ?.

The value of now assigned poly capacitor 9 between connections ? B? and ?D?.
is ? 0.1 ufd @ 630VDC ?.

The value of now assigned poly capacitor 10 between connections ? E? and ?F?.
is ? 0.22 ufd @ 1600VDC ?.

If you will resubmit, that with the proper values AND proper wiring connections , a schematic can be drawn with that info..

73's de Edd
.....

 

[Benny7440]

Both red cables only go to lamp's connector.
Aluminum wire 5 goes to the second wire of the grid if you look at it standing vertically. In any case, there're only 2 wires for electrocussion not three, so there's no center wire.

The 3 ? around 4 & 3 are the aluminum wires end of the grid and the big cap twisted.

The 3 ? at the right side are also the cap & grid wires twisted there.

As mentioned above, the grid is made up of two different wires running in a parallel way in a spiral until they get to the top.

There're 3 resistors: 2 Brown-Black-Green-Gold and 1 Brown-Black-Orange-Gold. From A to B there's a 100k one. From A to E there's a 10k one. From F to E there's the second 100k one.

The diodes go from E and D & from D and F. Can't read the characters printed on them. Both diodes are placed with the cathodes looking to the board.

Poly cap 7 & 9 are CBB21 104J400V and poly cap 10 is CBB22 824J400V, as printed on them.

 

[Benny7440]

I started to write a short message to be included but the attached photo was upside down so deleted it, went to edit the photo (rotate) and re-attach it but the text included at the beginning dissappeared. When I then tried to re-write it the text started to wrap itself at the beginning, making it giberish. BTW, is there a button for accessing the drafts the site is supposed to save as one writes every few minjtes?

Thanks!

 

[73's de Edd]

Sir Benny7440 . . . . .

I'm still being limited by the blurry pic and being unable to see the three caps side of the board close up .
Instead, will you confirm if I have accounted for all of the boards Copper Foil pads and the present placement of parts connections.

Look at each pad and count the number of solder connections made to it and verify .
I am curious if C only has the two connections shown being made into it.

MAKE REFERENCING TO . . . . . .
( With the need of a correction of the wide blade being AC COLD and the narrow blade of the AC plug being the HOT AC line connection. )

73's de Edd

 

[Benny7440]

Pad A has 3 conns.: Line in, C2, R1& R2.
Pad B " 2 " : Line in, C1 & Lamp 1.
Pad C " 1 " : Lamp 2.
" D " 3 " : C1, D1 & D2.
" E " 4 " : R2, D2, R3 & C3.
" F " 3 " : R3, D1 & C3.

The grid elements are connected to both sides of C3. In fact, C has only those conns.: C2 & Lamp 2.

Beware, in your diagram both diodes are placed in reverse polarity with respect to their real placement on the board...

 

[73's de Edd]

Sir Benny7440 . . . . .

Take the applied final info of yours at the bottom and now see if the parts layout and connections at the top, are now properly making a reverse engineered duplicate of the units board.

NEW PCB REFERENCING . . . . .



73's de Edd
. . . . .

 

[Benny7440]

Pad A has the line-in cable soldered at the hole for C2, R1 & R2 are also soldered there.
Pad B has indeed those four conns..
Pad C is as you state above.
Pad D also is as you put it above.
Pads E & F are right as you put it there.

 

[Benny7440]

You now have everything ok, Ed. Now, how to proceed, including another multiplying stage?

 

[Benny7440]

I've looked at the diagram above trying to imagine the ORIGINAL circuit (220 VAC input) connected to a power source for the sake of understanding the theory of operation but failed to do so, thinking of a sine wave as the source.

Can you help me understand the first few half-cycles?

 

[Benny7440]

Below I'm including an attachment containing a photo of a diagram of the circuit in question here and two questions about it:
1) what voltage should be expected to be delivered to the grid?
2) what's the process of charging C3 to the voltage needed?

Thanks in advanced!

 

[73's de Edd]

Sir Benny7440 . . . . .

Your unit was made for 220 VAC line use which rectifies to ~ 320-340VDC, but they additionally used a doubler circuit and ended up with ~ 640 VDC feeding to the mosquito shock grid.
In your case, with having only 120 VAC input, it needs to be voltage quadrupled.

The lower circuit would be, it but I have not had time to think out the cuts across F-prime or possibly, even part of E- prime also, in order to make additional pads to accommodate the extra parts on the same PCB.

ILLUSTRATION . . . . .


73's de Edd

 

[Benny7440]

Thanks for replying! I'm curious about the program you're using for the above diagrams: what's its name? Is it a free app?

 

[Benny7440]

Have stumbled with an autotransformer that might solve this issue (see the following):

https://www.electronicspoint.com/th...omething-that-resembles-a-transformer.290184/

Any info or comments are welcome!

 

[duke37]

A few more components in the Cockcroft-Walton multiplier will be smaller, lighter and more convenient than an external transformer.

 

[73's de Edd]

Sir Benny7440 . . . . .


Decisions . . .decisions . . .decisions . . . . . . and one of them has just been solved with the info provided on another post of yours, in your having found an AC auto-transformer..
That now can step up your lower 120VAC line voltage to the required 220 and its overall power capability easily meets the need of the Mosquito Zapper.

The task of making that Mosquito Zapper of yours work, by converting circuitry for 120VAC operation can now be eliminated, just by the mere use of that transformer.
You just need to see if you can mount it internally or enclosed in a plastic insulative housing at the bottom of the unit, such that no one can touch the unit or any of its wires.
SINCE, that isolation is what is already being accomplished with the Mosquito Zapper as it is now built.

As it was, the altering of the zapper grids high voltage supply was dependent upon converting to a voltage quadrupler in place of the existing circuits voltage doubler circuitry.
ADDITIONALLY there was the mini ULTRAVIOLET fluorescent lamp used to attract the varmints.

With 220 VAC power coming in on the original unit, it was merely dependent upon a 0.1 ufd capacitor being in series with the lamp on one of its power legs, with the other leg being ground.
As soon a power was applied to the unit the peak voltages of a 220 supply is being enough voltage to initially ionize the tube and then the direct power path thru the 0.1 ifd capacitance supplied the constant run voltage.
Instead of the use of a series inductance . . .aka ballast . . . . the capacitance reactance of the capacitor creates a constant power limiting of the amount needed by the lamp.
Can't do that with the lower 120 volts, as its voltage peaks never approach the amount needed to INITIALLY ionize the fluorescent lamp.


Using that autotransformer would involve having its 0V/ BLACK wire going to the COLD side of the Mosquito Zappers power lead wiring . That cold AC line cord wire would be lifted and a switch placed between it and its AC plug IF there is even a switch being incorporated on the unit. ( The cold AC cord line is the wire that connects to the WIDE blade of a polarized AC plug. )

The AC line cords HOT wire, which connects to the NARROW blade of the AC plug, would be lifted from its connection onto the PCB and then be connected to the BROWN wire of the autotransformer as its only connection.
The PCB connection that received that previous AC line cords HOT wire is now going to be receiving the
RED 220V wire of the autotransformer.

That will then have AC power coming into the primary of the autotransformer and its voltage upped to 220VAC to operate the Zapper at its designed voltage , and being as consumer safe as the Zapper was if the autotransformer case and its connections are insulated or inaccessible to ever be touched.

73's de Edd
.......................

I do some of my best fishing whenever it starts to rain . . . HOW ? . . . by moving over under a bridge.
The fish then keep crowding in under it to get out of the wet.