Mike, there are specialized chips for charging Li-Ion batteries. I have used one such chip from Microchip, they have step up (some step down) circuit built-in and they have charging curve built-in so users do not have to worry about it.mawyatt wrote:Lou,
Yes, Peter sells them. They also can control your various focus rails, since it has programmable motor and lead screw capability and doesn't require a computer/pad/smartphone to operate
http://www.mjkzz.com/product-page/stand ... ith-remote
The USB-C specification according to WiKi is a maximum of 5 volts for power. Since a typical LiOn cell is 3.7~4 volts, thus a simple USB-C non-switchmode regulator/charger could charge a single cell, but not a dual cell (like Nikon uses). A dual cell LiOn USB-C regulator/charger would require a more complex switchmode topology. My Nikon MH-25a charger is rated at 8.4 volts at 1.2 amps, this is for the Nikon EN-EL15 7 volt LiOn batteries.
Anyway, this is why I asked Peter about it.
Best,
Full electronic shutter
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Peter,mjkzz wrote:Mike, there are specialized chips for charging Li-Ion batteries. I have used one such chip from Microchip, they have step up (some step down) circuit built-in and they have charging curve built-in so users do not have to worry about it.mawyatt wrote:Lou,
Yes, Peter sells them. They also can control your various focus rails, since it has programmable motor and lead screw capability and doesn't require a computer/pad/smartphone to operate
http://www.mjkzz.com/product-page/stand ... ith-remote
The USB-C specification according to WiKi is a maximum of 5 volts for power. Since a typical LiOn cell is 3.7~4 volts, thus a simple USB-C non-switchmode regulator/charger could charge a single cell, but not a dual cell (like Nikon uses). A dual cell LiOn USB-C regulator/charger would require a more complex switchmode topology. My Nikon MH-25a charger is rated at 8.4 volts at 1.2 amps, this is for the Nikon EN-EL15 7 volt LiOn batteries.
Anyway, this is why I asked Peter about it.
Best,
If it's a step up converter chip then it must be a switchmode type of some sort, a continuous time regulator chip can only down convert. Switchmode converters can either step up or down as you mentioned. They also can produce considerable switchmode noise which can corrupt sensitive circuits unless extreme care is taken.
Best,
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike
~Mike
Peter,
I meant that the designer of the "USE" of these switchmode chips must be very careful with sensitive circuits, not the actual switchmode chip design. I'm sure these chips are well designed and thought out.
Long ago, we had a very complex sensitive chip that was used in part of a Motorola communications system, they were having "noise" problems and blamed our chip. A colleague went to investigate the problem and when he saw the O-scope traces, he immediately asked if they were using a Charge Pump (a switchmode type chip). They answered yes, he said that's the source of your noise problem, not our chip and then left!!
So the user of these switchmode chips must be careful with sensitive circuits, whereas linear type regulators produce much less noise and easier to apply. Our camera sensors have very low image noise levels, which implies sensitive circuits (amplifiers and ADC), so one must exercise extreme care when designing the camera with switchmode chips.
Best,
I meant that the designer of the "USE" of these switchmode chips must be very careful with sensitive circuits, not the actual switchmode chip design. I'm sure these chips are well designed and thought out.
Long ago, we had a very complex sensitive chip that was used in part of a Motorola communications system, they were having "noise" problems and blamed our chip. A colleague went to investigate the problem and when he saw the O-scope traces, he immediately asked if they were using a Charge Pump (a switchmode type chip). They answered yes, he said that's the source of your noise problem, not our chip and then left!!
So the user of these switchmode chips must be careful with sensitive circuits, whereas linear type regulators produce much less noise and easier to apply. Our camera sensors have very low image noise levels, which implies sensitive circuits (amplifiers and ADC), so one must exercise extreme care when designing the camera with switchmode chips.
Best,
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike
~Mike