Bolex H16 EL (and Beaulieu 16mm) power supply problem

[Tassanee Duca]

Hello everybody.
I present my problem concerning the power supply of two 16mm cameras.

Some time ago I bought a Bolex H16 EL (used but in good condition), with its original battery pack. Everything worked smoothly, until the battery stopped working.
A cinematographer, already owner of a similar camera, explained to me how to power it with a common lead-acid battery, which in his case worked very well and kindly sent me one of these batteries, the charger and a cable to connect it to the camera.
These the technical data of the lead-acid battery: Shimastu NPG 7,2-12,12V 7,2 Ah - The battery was always charged at a voltage of 12V.

Original camera battery technical data (from Bolex manual): SAFT VR-type Ni-Cd battery with low internal resistance and with a safety valve as protection against excessive pressure, nominal voltage 12 V-DC (alternating current excluded, because can destroying elements). 

Also from the Bolex manual: " The H16 EL can be powered by any 12V battery capable of supplying the necessary current:
voltage limits: 10,5 to 13,5 V DC, all function ensured.
                         16,5 V DC: limit for not damaging the electronic system.
Starting current: about 10A, for a fraction of a second;
normal consumption: from 0,8 to 1,2 A, depending of method of operation."

Regarding the battery elements, it is specified in the manual that: "the power packs for the H16 EL consist of a set of 10 1,35 V Ni-Cd storage batteries connetted in series."

 What happens when I connect the lead-acid battery (charged at 12V) to the camera: for a few minutes, everything works normally. I tried running the camera at various shooting speeds (10 to 50 fps) with a roll of film that I use for testing, and everything is smooth, including single shot.

After a few minutes, however, the problems begin: at any shooting rate that I set, the camera always runs at maximum speed, even if I set the single shot.
Furthermore, even if the camera is turned off, but always connected to this battery, after a while the camera will overheat until it becomes very hot ...

These problems did not exist when I was using the original Bolex battery.

What could be the cause of this problem? Maybe the voltage supplying the lead acid battery is not the correct one? Or is it not constant over time?

Also, I would like to solve the power supply problem for another camera, a Beaulieu 2016 Quartz. Also on this one, the original battery packs (7.5 V - 1.2 Ah) that I had have now come to an end (and how for those of Bolex, it is impossible for me to buy them again, both for their difficult availability and for their prohibitive cost).

Knowing that the Beaulieu for the S.8 are powered by normal rechargeable AA batteries (it seems to me 6 1.2V Ni-Cd batteries), I ask you if it is not possible to do the same with the "big sister" in 16mm?

For example, regarding the Beaulieu, I had thought of this solution: use a common battery holder, with 5 rechargeable 1.5 V Li-Ion batteries, connected in series, to reach the voltage of 7.5V (like that of batteries originals). In this way, I would have the correct voltage and an even higher capacity (about 2.5 Ah against 1.2 Ah of the originals).

I could do the same on the Bolex: battery holder of 8 rechargeable Li-Ion 1.5V 2500 mAh batteries, connect in series to get an output voltage of 12V.

My question is: can such a solution work (and will it not damage cameras)?

In conclusion, I am looking for a valid (and cheap) alternative to power these two cameras, still very valid and fully functional.
Unfortunately, I have no skills in the field of electrical engineering, so I ask if there is anyone who can confirm the validity of the solution I have thought of, and if it is not valid, to suggest another valid (and cheap) solution.

Thank you.
 

[Dom Jaeger]

9 hours ago, Tassanee Duca said:

What happens when I connect the lead-acid battery (charged at 12V) to the camera: for a few minutes, everything works normally. I tried running the camera at various shooting speeds (10 to 50 fps) with a roll of film that I use for testing, and everything is smooth, including single shot.

After a few minutes, however, the problems begin: at any shooting rate that I set, the camera always runs at maximum speed, even if I set the single shot.
Furthermore, even if the camera is turned off, but always connected to this battery, after a while the camera will overheat until it becomes very hot ...

These problems did not exist when I was using the original Bolex battery.
 

It sounds like your camera has a fault. Whether the new battery caused it is a question that would need investigation, but a normal 12V 7.2 Ah lead acid battery shouldn't damage the camera in any way. I would be looking at the power cable and plug, in case there is some shorting or high resistance causing problems. 

 

9 hours ago, Tassanee Duca said:

Also, I would like to solve the power supply problem for another camera, a Beaulieu 2016 Quartz. Also on this one, the original battery packs (7.5 V - 1.2 Ah) that I had have now come to an end (and how for those of Bolex, it is impossible for me to buy them again, both for their difficult availability and for their prohibitive cost).

Knowing that the Beaulieu for the S.8 are powered by normal rechargeable AA batteries (it seems to me 6 1.2V Ni-Cd batteries), I ask you if it is not possible to do the same with the "big sister" in 16mm?

For example, regarding the Beaulieu, I had thought of this solution: use a common battery holder, with 5 rechargeable 1.5 V Li-Ion batteries, connected in series, to reach the voltage of 7.5V (like that of batteries originals). In this way, I would have the correct voltage and an even higher capacity (about 2.5 Ah against 1.2 Ah of the originals).

I could do the same on the Bolex: battery holder of 8 rechargeable Li-Ion 1.5V 2500 mAh batteries, connect in series to get an output voltage of 12V.

My question is: can such a solution work (and will it not damage cameras)?
 

Any battery solution between 7.2V and 7.5V should work, as long as the capacity is OK. The original R16 cells went as low as 500mAh, so 2.5Ah should be more than enough. You can't have too much capacity, the camera will just draw what it needs, but more capacity usually equals bigger cells and more weight or higher cost. What damages an appliance is too much voltage (ie more than say 10V for the Beaulieu or 16.5V for the Bolex) or reversing polarity or voltage leaking to the chassis (usually due to a faulty power plug or socket). Heat is usually due to a high resistance point, maybe a poor connection or corrosion or a faulty component. Reverse polarity can cause a short circuit that causes heat, but usually something smokes pretty quick.

If you're not electrically savvy I would probably take the Bolex with battery and cable to an electrical repair shop, or a Bolex specialist. 

 

[Tassanee Duca]

Hi Dom Jaeger,
I thank you for the answer.
 

Quote

a normal 12V 7.2 Ah lead acid battery shouldn't damage the camera in any way. I would be looking at the power cable and plug, in case there is some shorting or high resistance causing problems.

 ...Reverse polarity can cause a short circuit that causes heat, but usually something smokes pretty quick.
 

The Bolex just heats up, it doesn't emit any smoke, so I don't think it's reverse polarity, but an anomalous resistance (also because with the original battery I had shot several rolls of film without any problem ..).
The electrical cable that connects the lead acid battery to the camera was handcrafted, perhaps the problem could be in the cable.

With a tester, I will measure the output voltage from the cable, on the socket; if in the cable (or in the connection with the socket) there is an abnormal resistance, the output voltage should be less than 12V ...
 

Quote

What damages an appliance is too much voltage (ie more than say 10V for the Beaulieu or 16.5V for the Bolex) or reversing polarity or voltage leaking to the chassis (usually due to a faulty power plug or socket).
 

This is important. So, I will be able to create with a stylus battery holder (with 5 Li-Ion 1.5V batteries connected in series), a 7.5V "battery pack" for the Beaulieu, and another (with 8 1.5V batteries) 12V for the Bolex, which by the way will be lighter than the lead acid battery.
Of course, before connecting these battery packs to the cameras, I will check their output voltages with the tester...

[Tassanee Duca]

 

About Bolex problem:

Hi, as you suggested me, I checked the cable I used to connect the 12V lead battery to the Bolex; it results that on the output poles, there are 12 V both on the poles that feed the motor (poles 1 and 4), and 12 V on the poles that feed the electronic circuit (poles 2 and 3). See diagram.

Now, 12V to power the electronic circuit seems to me too many ... maybe that's the reason why, after a few minutes of operation, the camera motor, at whatever shooting rate I had set, went at maximum speed, and after a while the whole body of the camera was getting hot ...

I did another test, replacing the previous cable with another cable that powers only the camera motor (poles 1 and 4), I turned several test rolls (more precisely, a roll that I advanced and then rewind with the backward of the camera and then forward again) and nothing strange happened, the camera remained "cold", only it always shot at the same speed (I think 18 fps) at every shooting speed that I set, even if I set the single frame, it went at 18 fps. This is probably due to the fact that the electronic circuit was not powered.

Basically, by powering only the motor with 12 V, it advances at 18 fps and also reverses, in addition, the exposure meter cell works correctly.

So, to solve the problem and have the full functionality of the camera, I need to know exactly what voltage the electronic circuit must be powered with.
Who can give me this information?
Thanks

[Floris Vanhoof]

I've been searching and asking around for a Bolex EL technical manual or camera technician for a while and can't find any. Definitely following this and curious for pictures if anyone opens your camera.