I wanted to learn the following about my K200D, the cutoff battery voltage/monitor reading, and current drawn during different functions.
The batteries in the camera are in series. The battery toward the lens side of the camea is the plus, the battery 3rd from the lens side is the minus. There is a small switch activated when the battery door closes, that must be pushed in to power up the camera.
Here is what I observed:
Batteries were out of my camera for several days I placed fully charged batteries in the camera, camera wouldn’t turn on. Put those in the Maha charger and noticed they were full. Put in the second set and camera still didn’t turn on. Within a minute, tried the camera again and it came on with no problem. It was like there was a large capacitor that had to charge first???
I was able to connect directly to the battery clips, pushing in the little switch, the camera came on. I had a 25 amp adjustable supply allowing voltages down to 1 volt. I started with at 5.2 volts and zeroed in on 4.8 volts. I watched the voltage with two digital meters at the supply output both were exactly the same. The Beckman 223 reading is the left value/Fluke 87 is the right reading
4.59 Volts NO Turn On
4.60/4.596 Turns ON, Shutter trips every time, Flash charges and works
4.65 volts Camera Came On, Bat Monitor Empty
4.69 volts Camera Came On, Bat Monitor Empty
4.73 volts Camera Came On, Bat Monitor Full
4.76 volts Camera Came On, Bat Monitor Full
4.78 volts Camera Came On, Bat Monitor Full
4.79 volts Camera Came On, Bat Monitor Full
4.8 volts Camera Came On, Bat Monitor Full
Here is what is very interesting. If I very slowly started turning down the voltage, the battery monitor didn’t change from full, even if the power supply was down to 2.6 volts. It was like a charged capacitor was maintaining the operation. In order to catch the threshold, the supply voltage was adjusted a small fraction, the bottom switch was depressed and it then would show the difference after camera came on.
Turn ON is 4.60 volts. I tripped the shutter 4 times, popped up the flash tripped shutter two, it worked every time with no flicker on the 4.60 volts supply. ON MY CAMERA 4.60/4.596 VOLTS IS THE LIMIT LOW, STILL WORKS AT THAT VOLTAGE! Readings shown are a Beckman reading on the left and Fluke on the right.
Never saw half a battery monitor, ever. Above 4.72/4.715 Battery Monitor was full. The above voltages were straight from the power supply, no measuring resistance in series.
The Current Draw Measurements were made at about 5.2 volts, with a lab type HP 0.1 ohm shunt for converting mA to mV for the Scope meter and double checking that with the Fluke 87 in series. The Fluke 87 was set for Record in Min Max with 100 mS capture. The HP 0.1 ohm shunt fed a Fluke Scopemeter for comparison of accuracy, both the same readings.
Functions of the K200D:
Turn camera on: Quick short spike of 1296 mA ( within a second)
First Stage, Camera On, LCD Screen On, 260 mA
Second Stage, Camera On, LCD Screen Off 149 mA for about 10 seconds
Third Stage, Camera On in standby 87 mA
Fourth Stage Sutter Tripped 1.484 mA for less than a second
Flipped up the Flash and Charge, for a brief moment 1.480 mA
I used two digital meters, the Beckman 223 and Fluke 87B. Where the above voltage reading are shown, i.e. 4.60/4.596 those are from the Beckman and the Fluke at the output of a 25 amp voltage regulated/adjustable dc power supply.
I didn't write it down, but it seems during a 30 sec time expose, after the initial quick 1484 mA spike, the current draw was 400 mA with shutter open.
I wish to thank UnknownVT who collaborated with me all week and corrected my typos and gave me additional ideas. The part that was confusing at first is getting past a point where the camera needs a short time after power has been removed to establish a point where it will turn on.
Not a part of these measurements shown above, but FYI only. Regarding the connector for an external power supply, I was surprised how many styles and sizes are listed in Wikipedia. Those in the US, Germany, Din, Japan all are different. A 5mm OD 2mm ID easily goes into the camera, but the I.D. is too big creating an intermittent connection . Closest to what I could purchase locally from Radio Shack was the Adaptaplug “C” part # 273-1706. Its size is listed as 4.7 mm O.D. 1.7 mm I.D. These are made plug on their power supplies. I soldered two wires onto the plug and tested with an external power supply and it had no signs of being intermittent.
Dave
