Remington Shaver HC6550 not to full Power

[THX1138]

DAMN . . .Sam !. . . . .Yore Rat Shak meter fo' certain . . .shore doesn't like your shaver motors, particularly the second one.
Lets see if that is due to HEAVY induced back EMF from the motor windings, at sequential brush / commutator disruptions .

See if those PETER METER leads will pull out JUST enough so as to expose bared metal banana probe contact.
Then you Press / lay down / wrap around a 1N4007 diode such that its silver banded wire lead cathode rests against the RED meter probe
gap and the other lead contacts the BLACK meter wires gap. OR you might need to use clip leads or ? sheer ingenuity.
Just be sure that only + power connection comes into that RED + meter lead, other wise its a forward conducting power diode across the power source . . .BANG . . . . BANG diode.
EXPECTING that erratic meter pointer to then somewhat or completely settle down.
Did you ever disable / disconnect a motor (s) . . . . such that you only had one motor running at a time ?

73's de Edd . . . . .

Don't think I'll be able to peel the MM leads to add the diode between them if that's what you're asking. But I can say that the MM leads/probes are labeled as 1000V CATII 2A if that makes a difference with the EMF that you mentioned.

 

[THX1138]

A better picture of the printed label on the battery.

 

[CircutScoper]

Let's put it this way. If you look at my 3rd post you will see a picture of the device with a clear view of the batteries. Placing the negative probe from my MM on top of the battery to the left and then placing the positive probe on the bottom of the right battery gives me 4.2V. when the device is on and off. Likewise I get the same reading placing the negative probe on top of the right battery and the positive probe on the bottom of the right battery and vice versa with the other battery.

What voltage do you read with one probe on the bottom of one battery and the other probe on the bottom of the other?

 

[73's de Edd]

Sir THX1138 . . . . .


Nope . . . . . no inference made, as to "butchering" your test leads.
Instead this procedure . . . since mine eyes cannot see that meters inserted test leads . . . .

Radio Shack . . .22-109

https://picclick.com/RadioShack-17-Range-Analog-Multimeter-224571118370.html#&gid=1&pid=1


https://www.electronicspoint.com/fo...49817049472_7504292328984890435_n1-jpg.55208/


I was just thinking about pulling both, plugged in BANANA JACK leads . . . . out JUST enough to expose some contact areas, so that a diodes bare long lead lengths, could be twirled across each according , then exposed contact area.
BUT . . . in looking at THAT meter and its test leads, that might not be possible.
BECAUSE . . .
That units . . .CAT I I . . . ratings might also require that those banana connectors be SHROUDED / insulatively.
See the left pair, that I hoped that your unit used and the exposed metal contact area possibility . .VERSUS . . the right pairs complete insulative shrouding of the potential contact area.





So you would need to go out to the exposed test lead end propers, to be able to place / clip connect an EMF damping / shunting diode in circuit.

OBSERVING PROPER INSTALL POLARITY.

As it is, your WILDLY fluctuating / variant DC voltage readings mean nothing.
PROBABLY due to simultaneous . . . . motor induced . . .back EMF voltage, also being present / superimposed . . . . . dependent upon the newly in circuit diode, to dampen those down to 500-700 mv.

Thaaaaaaaaaaaaaaaaaasit . . .

TECHNO ADDENDA . . . . .
I see that unit only has a 25 ma and 250 ma current measuring range, when inserted in series with your circuits power flow delivery.
Myself . . . .I would be in need of 1 amp and 10 amp ranges also.
The same procedure, just covered, could acquire 1 amp and 10 amp current ranges, if you temporary installed 1 ohm or 0.1 ohm current resistor shunts . . . . hopefully 5 watt ratings . . . if you don't tarry too long on your in circuit 10A readings.
The current in amps is being read out on the 10 V DC scale. .



73's de Edd . . . . .

On the freeway . . . . have you ever noticed... categorically . . . .anybody going slower than you is an idiot. And anyone going faster is a maniac


.

 

[THX1138]

What voltage do you read with one probe on the bottom of one battery and the other probe on the bottom of the other?

Unless I am doing something wrong, it's always 4.2V.

 

[CircutScoper]

Unless I am doing something wrong, it's always 4.2V.

Top to top?

 

[THX1138]

Top to top?

Top ends are negative.

 

[CircutScoper]

Top ends are negative.

What voltage do you measure between them? Reverse the meter leads if necessary.

 

[THX1138]

What voltage do you measure between them? Reverse the meter leads if necessary.

Sorry. I meant to say that top to top gives me a 0V reading and the bottom gives me about 8.4V reading while off.

 

[CircutScoper]

Sorry. I meant to say that top to top gives me a 0V reading and the bottom gives me about 8.4V reading.

So the batteries ARE connected in series, supplying a total of 8.4V to drive the motors, but less than half of that actually makes it to the motor terminals.

The key question would therefore seem to be : Where is all that voltage being lost? I still think that if you probe the conduction path step by step, you can find that point of poor conduction and power loss.

 

[THX1138]

So the batteries ARE connected in series, supplying a total of 8.4V to drive the motors, but less than half of that actually makes it to the motor terminals.

The key question would therefore seem to be : Where is all that voltage being lost? I still think that if you probe the conduction path step by step, you can find that point of poor conduction and power loss.

Also while the device is on the bottom reads .2V or .4V loss and the top reads .2V or .4V gain.

 

[CircutScoper]

Also while the device is on the bottom reads .2V or .4V loss and the top reads .2V or .4V gain.

Are you saying that the top-to-top reading rises from 0V to 0.4V while the motors are running?

 

[73's de Edd]

What voltage do you read with one probe on the bottom of one battery and the other probe on the bottom of the other?

Verbal / semantics ambiguity lets me interpret that more than one way .

REFERENCING MARKUP . . . . . . . . .


I can see the compression indentation rings ( broken red dotted lines depictions) present on all 18650 and 14650 'lil brother cells, that are being at their + ends .
As I see these . . .REFERENCE A gets connected to bottom left corner of PCB.
REFERENCE B gets jumpered to REFERENCE C
REFERENCE D connects to bottom right corner of PCB.
Three transistor or FET's are visible in YELLOW circles .

Cutter motor BLACK lead is being in the - terminal REFERENCE A proximity and probably passes down to connect into REFERENCE A using the heavy foil buss seen..

Cutter motor RED lead end seems to be end imbedded into 2 larger and 1 minor foil paths that travel up he board towards that top YELLOW CIRCLE semiconductor.
I tend to suspect that cell REFERENCE D has sent a heavy foil buss straight up and then over to be seen coming in towards that top
YELLOW CIRCLE semiconductor , from its right.
Then . . . uP signal input . . . . keys that cutter motors power.

As for that separate vacuum motor . . . . . might the BLACK of the two bottom left corner leads be one of the vacuum motor leads, and it gets direct connected to REFERENCE A foil. Then the bottom center YELLOW CIRCLE semiconductor is used for vacuum motor switching.
Turn on / off is remoted down and into it from the topside u/P.

In interpreting this circuitry, another consideration is at the top YELLOW CIRCLE.
I could be that semiconductors path is connecting its right side connected foil buss to the foil buss that is on its left. That completed circuit is being the jumpering function of REFERENCE B to
REFERENCE C. If fault or over current consumption is monitored, that semiconductor is switched to open circuit to stop battery power flow.

Make some initial voltage readings between those points, and expecting / finding no voltage present initially, and then, changing to ohmming out that circuit and reading 0 ohm / connectivity should confirm that.


73's de Edd . . . . . .



My cross the crik neighbor, Delmer Pee Dumbnuttz . . . . . . just finished taking an IQ test and they said the results came back negative.


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[THX1138]

While off B+C=OV, A+D=8.4V, B+A+4.2V, C+D=4.2V. While on B+C=0.2V, A+D=7.8V, B+A=4.0V, C+D=4.0V. A better view of the circuitry.
https://www.imagevenue.com/ME14X5RF
https://www.imagevenue.com/ME14X5SO
https://www.imagevenue.com/ME14X5SP