Answer:
not sure if this helps but
Answer:
battery life in year = 9 years and 48 days
Explanation:
given data
Battery Ampere-hours = 1.5
Pulse voltage = 2 V
Pulse width = 1.5 m sec
Pulse time period = 1 sec
Electrode heart resistance = 150 Ω
Current drain on the battery = 1.25 µA
to find out
battery life in years
solution
we get first here duty cycle that is express as
duty cycle = 
...............1
duty cycle = 1.5 × 
and applied voltage will be
applied voltage = duty energy × voltage ...........2
applied voltage = 1.5 × × 2
applied voltage = 3 mV
so current will be
current = 
................3
current = 
current = 20 µA
so net current will be
net current = 20 - 1.25
net current = 18.75 µA
so battery life will be
battery life = 
battery life = 80000 hours
battery life in year = 
battery life in year = 9.13 years
battery life in year = 9 years and 48 days
Answer:
There are three common methods of charging a battery; constant voltage, constant current and a combination of constant voltage/constant current with or without a smart charging circuit.
Constant voltage allows the full current of the charger to flow into the battery until the power supply reaches its pre-set voltage. The current will then taper down to a minimum value once that voltage level is reached. The battery can be left connected to the charger until ready for use and will remain at that “float voltage”, trickle charging to compensate for normal battery self-discharge.
Constant current is a simple form of charging batteries, with the current level set at approximately 10% of the maximum battery rating. Charge times are relatively long with the disadvantage that the battery may overheat if it is over-charged, leading to premature battery replacement. This method is suitable for Ni-MH type of batteries. The battery must be disconnected, or a timer function used once charged.
Constant voltage / constant current (CVCC) is a combination of the above two methods. The charger limits the amount of current to a pre-set level until the battery reaches a pre-set voltage level. The current then reduces as the battery becomes fully charged. The lead acid battery uses the constant current constant voltage (CC/CV) charge method. A regulated current raises the terminal voltage until the upper charge voltage limit is reached, at which point the current drops due to saturation.
Answer:
sorry if wrong
Explanation:
One sheave means that you are using a single drum winder. They are the worst! Double drum winders control easier, brake better and are much more efficient. They save time ( two skips or cages) and can be clutched to perform faster shift transport. A single drum is slow, unbalanced and can be a nightmare if it trips out during hoisting. If the brake system is not perfect it can be a real hairy experience. For a runaway single drum, there is no counterbalance effect. It always runs to destruction. With a double drum, the driver still has a chance to control the winder to a certain extent and he has two sets of brakes to rely on. A single sheave could also mean a shaft with a single compartment. No second means of escape unless there are ladders or stairways. Not a very healthy situation.
Those are just a few points. I am sure much more can be said in favor of a double drum winder and two or more sheaves in the headgear. Most of the shafts I have worked at have multiple winders and up to ten compartments. They all have a small single drum service winder for emergencies and moves of personnel during shift times. They are referred to as the Mary - Annes. Apparently, the name originated in the U.K. where an aristocratic mine owner named the first such winder after his mistress.
