Цитата:
Сообщение от Андрей Крукович
Наверно будет показанно максимальное потребление тока?
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Добрый день,
Боюсь, что я не могу объяснить это на русском языке, поэтому мне придется сделать это на английском языке.
Я надеюсь, что я не тормоз любых правил, делая это.
Цитата:
Правила часового форума WWW.WATCH.RU
Перед тем как начинать писать на данном форуме прошу ознакомиться со следующими правилами.
1. Для общения на форуме используйте только русский или английский языки.....
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OK, we have several points to clear before we go on. Circuit diagram shown in message
#27 had only one purpose, that being only to show a principle of measuring amplitude of an impulse.
In my further communication with Andrey Krukovich, in private, I suggested another practical circuit, which is shown in figure 7, page number 4 in
AN-294 , and I shall explain my reasoning for suggesting it.
In the case of quartz watches there are only two values of current to be measured. The quiescent current of the electronics module and the high current, stepper motor driving impulse, which occurs at one second intervals, with some watches intervals are 4s or 5s and in rare cases the interval is longer. To measure the quiescent current of the electronics module any digital multimeter with hold function can be used, even the cheapest ten euro Chinese multimeters have that function.
I have chosen sample and hold circuit design that incorporates trigger that allows user to decide when sampling is going to happen. That is usually accomplished by simple processing of the input signal. In cases where there are present more impulses that vary in amplitude, by creating a simple voltage window we can choose which impulse shall serve as our trigger.
The circuit of figure 7 needs a low going impulse to trigger the sampling, which can be inverted rising edge of the exact impulse that we want to measure.
This way we do not have averaging of various impulses, since we know what our good signal should look like then it is easy to set "sensitivity" control to a desired narrow span of voltage value.
Once that the sampling is done, hold function takes place and if only one impulse is allowed to trigger the sample and hold circuit we have our wanted parameter reading and the value can be read by using any high input impedance (e.g. 10 M Ohm) multimeter.
Now, personally I prefer, in case of quartz watches to monitor actual current consumed by stepper motor rather than voltage, but monitoring the voltage drop of the battery cell in the moment of high current drain may too be a nice way to design a simple indicating instrument that shall show us the state of the watch circuit.
Keep in mind that the voltage drop at the battery cell caused by stepper motor driving impulse is directly proportional to the current drain from the battery cell, and almost all noise, otherwise present, is eliminated.
If there is going to be a collective effort in designing a simple device that shall help in servicing of quartz watches I shall certainly help.
Personally I do not have a need for it as I do not service quartz watches and in the rare cases when I cannot say NO, I have at my disposal fully equipped electronics laboratory, while just a simple digital storage oscilloscope does all the measuring that I may need.
Incidentally I regularly use a digital storage oscilloscope in the repair of all mechanical watches. It is connected to the audio output of the Vibrograf B200 timing machine for the escapement analysis, which is an irreplaceable tool in diagnosing faults in it's workings, indicating some faults that cannot be seen with naked eye and are difficult to see or spot even with a use of a microscope.
As a conclusion, all of the above mentioned is quite possible to be done using a simple microcontroller and a handful of components. I have knowledge but have neither the time nor will to do it myself, but I am sure that there are many younger people here at the forum who have it all, time, willingness and knowledge to do it.
С уважением
Душан