Project:Pi-Power topping board - Revision history

Montyphy: Montyphy moved page Projects/Pi-Power topping board to Project:Pi-Power topping board

2013-06-03T14:49:05Z

Montyphy moved page Projects/Pi-Power topping board to Project:Pi-Power topping board

← Older revision

Revision as of 14:49, 3 June 2013

Sci at 00:42, 29 May 2013

2013-05-29T00:42:43Z

← Older revision		Revision as of 00:42, 29 May 2013
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	600, 250 and 150mA outputs. Up to 93% efficiency.		600, 250 and 150mA outputs. Up to 93% efficiency.
	I2C appears for control, not monitoring.		I2C appears for control, not monitoring.

			[[Category:Projects]]

Sci at 12:08, 1 December 2012

2012-12-01T12:08:43Z

← Older revision		Revision as of 12:08, 1 December 2012
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	==Brief==		==Brief==

	Creation of a power supply battery board for the Raspberry Pi computer, fit for long-term/perminant instalation (IE; not a hack-job).		Creation of a power supply battery board for the Raspberry Pi computer, fit for long-term/perminant instalation (IE; not a hack-job) and adaptable.
	~~If sucessful, potential funding source for Hackspace.~~
	Codename; "Project Custard"		Codename; "Project Custard"

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	* Con		* Con
	** Both inputs 5v		** Both inputs 5v
			====LT3690====
			Use with LTC4155 on 3A input? High efficiency, up to 36v input. Good contender.

	===LTC4098===		===LTC4098===

Artag: /* Power requirements */

2012-11-06T09:56:42Z

Power requirements

← Older revision		Revision as of 09:56, 6 November 2012
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	Since it's a linear regulator, the input current is the output current + internal use. The internal use is quoted at typically 6mA (quiescent current) - high, but a small proportion of the Pi's total. The main loss in that regulator is because it's passing up to 750mA and dropping 1.7V. That's 1.275 watts out of a total Pi consumption of 3.75, which is where the calculation of 1/3 comes from. --[[User:Artag\|Artag]] ([[User talk:Artag\|talk]]) 09:55, 6 November 2012 (UTC)		Since it's a linear regulator, the input current is the output current + internal use. The internal use is quoted at typically 6mA (quiescent current) - rather high, but only a small proportion of the Pi's total. The main efficiency loss in that regulator is because it's passing up to 750mA and dropping 1.7V. That's 1.275 watts out of a total Pi consumption of 3.75, which is where the calculation of 1/3 comes from. --[[User:Artag\|Artag]] ([[User talk:Artag\|talk]]) 09:55, 6 November 2012 (UTC)

	==Charge/power controllers==		==Charge/power controllers==

Artag: /* Power requirements */

2012-11-06T09:56:11Z

Power requirements

← Older revision		Revision as of 09:56, 6 November 2012
Line 36:		Line 36:


	Since it's a linear regulator, the input current is the output current + internal use. ~~This~~ is quoted at typically 6mA (quiescent current) - high, but a small proportion of the Pi's total. The main loss in that regulator is because it's passing up to 750mA and dropping 1.7V. That's 1.275 watts out of a total Pi consumption of 3.75, which is where the calculation of 1/3 comes from. --[[User:Artag\|Artag]] ([[User talk:Artag\|talk]]) 09:55, 6 November 2012 (UTC)		Since it's a linear regulator, the input current is the output current + internal use. The internal use is quoted at typically 6mA (quiescent current) - high, but a small proportion of the Pi's total. The main loss in that regulator is because it's passing up to 750mA and dropping 1.7V. That's 1.275 watts out of a total Pi consumption of 3.75, which is where the calculation of 1/3 comes from. --[[User:Artag\|Artag]] ([[User talk:Artag\|talk]]) 09:55, 6 November 2012 (UTC)

	==Charge/power controllers==		==Charge/power controllers==

Artag: /* Power requirements */

2012-11-06T09:55:45Z

Power requirements

← Older revision		Revision as of 09:55, 6 November 2012
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	Needs more research. Theoretical maximum will probably need adding up the max ratings on all component datasheets, or running stress-tests while on seperate current-monitoring power supplies.		Needs more research. Theoretical maximum will probably need adding up the max ratings on all component datasheets, or running stress-tests while on seperate current-monitoring power supplies.
	Elinux has monitored total 5v power use at 750mA during 1080p video playback: http://elinux.org/RPi_Performance#Power		Elinux has monitored total 5v power use at 750mA during 1080p video playback: http://elinux.org/RPi_Performance#Power



			Since it's a linear regulator, the input current is the output current + internal use. This is quoted at typically 6mA (quiescent current) - high, but a small proportion of the Pi's total. The main loss in that regulator is because it's passing up to 750mA and dropping 1.7V. That's 1.275 watts out of a total Pi consumption of 3.75, which is where the calculation of 1/3 comes from. --[[User:Artag\|Artag]] ([[User talk:Artag\|talk]]) 09:55, 6 November 2012 (UTC)

	==Charge/power controllers==		==Charge/power controllers==

Sci at 02:51, 6 November 2012

2012-11-06T02:51:27Z

← Older revision		Revision as of 02:51, 6 November 2012
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	** Batt temp		** Batt temp
	** Batt age/condition (software/logging)		** Batt age/condition (software/logging)
			** Per voltage bus current monitoring
	** etc..		** etc..
	* Lithium-Ion/Lithium-Poly battery pack for low weight		* Lithium-Ion/Lithium-Poly battery pack for low weight

Sci at 02:49, 6 November 2012

2012-11-06T02:49:12Z

@@ Line 34: / Line 34: @@
 ==Charge/power controllers==
 ==Switching regulators==
-Initial findings presuming 800mA-1000mA per output.
+Initial findings presuming 800mA-1000mA per output. I2C less important here if power controller can monitor current use.
 ===Single output===
 ===Dual output===
 ===Triple output===

Sci at 01:17, 6 November 2012

2012-11-06T01:17:14Z

← Older revision		Revision as of 01:17, 6 November 2012
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	==Spec==		==Spec==

	* Two to three outputs; 5v, 3.3v and an adjustable output for peripherals (EG: 6v for (small) servos or 3.7v for HUD power).		* Two to three outputs; 5v, 3.3v busses and an optional adjustable auxilary output for peripherals (EG: 6v for (small) servos or 3.7v for HUD power).
	** Switching regulators for higher efficiency		** Switching regulators for higher efficiency
	* Status to Pi through I2C bus (to prevent taking up single-use I/O pins)		* Status to Pi through I2C bus (to prevent taking up single-use I/O pins)
Line 36:		Line 36:

	==Switching regulators==		==Switching regulators==
			Initial findings presuming 800mA-1000mA per output.
	===Single output===		===Single output===
	===Dual output===		===Dual output===
	===Triple output===		===Triple output===

Sci: Created page with "==Brief== Creation of a power supply battery board for the Raspberry Pi computer, fit for long-term/perminant instalation (IE; not a hack-job). If sucessful, potential fundin..."

2012-11-06T01:13:33Z

Created page with "==Brief== Creation of a power supply battery board for the Raspberry Pi computer, fit for long-term/perminant instalation (IE; not a hack-job). If sucessful, potential fundin..."

New page

==Brief==

Creation of a power supply battery board for the Raspberry Pi computer, fit for long-term/perminant instalation (IE; not a hack-job).
If sucessful, potential funding source for Hackspace.
Codename; "Project Custard"

==Spec==

* Two to three outputs; 5v, 3.3v and an adjustable output for peripherals (EG: 6v for (small) servos or 3.7v for HUD power).
** Switching regulators for higher efficiency
* Status to Pi through I2C bus (to prevent taking up single-use I/O pins)
** Current use (ideally on each bus)
** Batt voltage
** Charging/batt-power status
** Batt temp
** Batt age/condition (software/logging)
** etc..
* Lithium-Ion/Lithium-Poly battery pack for low weight
* Able to charge from USB and/or other higher current source (12v car supply or higher rated mains adaptor)
* 10-12hr min uptime

===optional===
* Same PCB to allow external power only through leaving charger section unpopulated/jump-linked

==Power requirements==

I've looked up the linear regulator used on the Pi, it's a 17-33G, rated for up to 800mA. Ohms law says that's 2.64Watts. But that's just output, I can't see anything about it's efficiency to infer it's input current. I hear the figure of 1/3rd power being converted to heat banded about though, so while it needs confirming it's something to be going on with. Would make the input to the regulator higher than the spec for the entire board. So it's safe to say the regulator capacity is not fully utilised.
The spec power for the whole Pi is 700mA at 5v (3.5watt). Presuming a magic regulator that's 100% efficient, that's 860mA left to the 5v side.

Since these are inherently flawed figures though, it's only enough to give us a ballpark maximum current of about 800mA per 5/3.3v input.

Needs more research. Theoretical maximum will probably need adding up the max ratings on all component datasheets, or running stress-tests while on seperate current-monitoring power supplies.
Elinux has monitored total 5v power use at 750mA during 1080p video playback: http://elinux.org/RPi_Performance#Power

==Charge/power controllers==

==Switching regulators==

===Single output===
===Dual output===
===Triple output===