Electricity Primer - Revision history

Mparadis: Redirected page to Improving Phidgets Hardware Reliability

2019-10-22T18:53:25Z

Redirected page to Improving Phidgets Hardware Reliability

Mparadis at 15:53, 7 June 2018

2018-06-07T15:53:30Z

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	===Sensor and Motor Wiring===		===Sensor and Motor Wiring===
	All Phidgets sensor class devices (products whose part numbers start with 11 such as the 1129) use a 3-wire channel [{{~~SERVER~~}}~~/?view=comparetable&rel=Phidget%20Cables Phidget cable]~~ for power and data transmission. Similarly, all our motors and load cells use multichannel wire interfaces. As mentioned previously, USB spec limits cables to 5m, this is not the case for these wires. The biggest concerns are electromagnetic interference (EMI) and voltage drop. In general you should be able to run these wires over significant distances (30m or more) with the load cells in particular having very long range. If EMI starts causing issues you can always use ferrite beads on the cable near the sensor or motor and the controller to reduce noise.		All Phidgets sensor class devices (products whose part numbers start with 11 such as the 1129) use a 3-wire channel {{CT\|PhidgetCable\|Phidget cable}} for power and data transmission. Similarly, all our motors and load cells use multichannel wire interfaces. As mentioned previously, USB spec limits cables to 5m, this is not the case for these wires. The biggest concerns are electromagnetic interference (EMI) and voltage drop. In general you should be able to run these wires over significant distances (30m or more) with the load cells in particular having very long range. If EMI starts causing issues you can always use ferrite beads on the cable near the sensor or motor and the controller to reduce noise.

	For more information on the effects of long wires and how to mitigate them, refer to our [[Effects of Long Wires]] guide.		For more information on the effects of long wires and how to mitigate them, refer to our [[Effects of Long Wires]] guide.

Mparadis at 16:49, 29 November 2017

2017-11-29T16:49:47Z

← Older revision		Revision as of 16:49, 29 November 2017
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			<metadesc>Reliable electrical systems demand knowledge about how multiple devices with power supplies and data lines interact. Learn more at Phidgets.com.</metadesc>
	[[Category: Primer]]		[[Category: Primer]]

Lmpacent at 19:55, 5 July 2017

2017-07-05T19:55:05Z

Show changes

Lmpacent: /* Introduction */

2017-07-05T18:14:26Z

Introduction

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	==Introduction==		==Introduction==
			Designing reliable systems is quite hard. The main challenge is the design of reliable building blocks (i.e. circuit and board layouts, from which to create your system). Phidgets does the majority of this work for you, and, once you have reliable building blocks, designing a reliable system from them is much easier.

	Design of reliable systems is really, really hard. The main challenge is the design of reliable building blocks - i.e. circuit and board layouts - from which to create your system. Phidgets does the majority of this work for you. And, once you have reliable building blocks, designing a reliable system from them is much easier.		However, you can still make a unreliable system out of Phidgets. In fact, if you are building a more complex system than the common examples we show through our documentation, and you have limited experience in complex electrical design, you will likely introduce design flaws that will make your system unreliable.

	However, you can still make an unreliable system out of Phidgets. In fact, if you are building a more complex system than the common examples we show through our documentation, and you have limited experience in complex electrical design, you will ~~probably - and unintentionally -~~ introduce design flaws that will make your system unreliable.

	There are two reasons why you should read this primer:		There are two reasons why you should read this primer:
	# You want to build a complex system, more complex than we illustrate in our documentation. To succeed, you need to understand concepts.		# You want to build a complex system, more complex than we illustrate in our documentation. To succeed, you need to understand certain concepts.
	# You understand how to make your system work, and you want to ensure it is well designed for maximum reliability and/or precision.		# You understand how to make your system work, and you want to ensure it is well designed for maximum reliability and/or precision.

Mparadis: /* Choosing a Battery */

2017-06-08T20:10:32Z

Choosing a Battery

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	Then, for lead-acid batteries, a typical battery is tested from full to complete drain over 20 hours by the manufacturer to obtain the advertised amp-hour rating. Draining a battery at a faster rate than this will result in even more reduction in capacity, by 10% or even more. This due to [http://en.wikipedia.org/wiki/Peukert%27s_law Peukert's Law].		Then, for lead-acid batteries, a typical battery is tested from full to complete drain over 20 hours by the manufacturer to obtain the advertised amp-hour rating. Draining a battery at a faster rate than this will result in even more reduction in capacity, by 10% or even more. This due to [http://en.wikipedia.org/wiki/Peukert%27s_law Peukert's Law].

	There are plenty of ~~[http://www.google.ca/search?&q=battery+calculator~~ battery calculators] around the Internet which take most or all of these additional factors into account when recommending an amp-hour rating. For longer-term installations, the solar power online community has some excellent resources.		There are plenty of battery calculators around the Internet which take most or all of these additional factors into account when recommending an amp-hour rating. For longer-term installations, the solar power online community has some excellent resources.

	====Setting up Multiple Batteries====		====Setting up Multiple Batteries====

Patrick at 15:06, 7 April 2017

2017-04-07T15:06:35Z

← Older revision		Revision as of 15:06, 7 April 2017
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	==Introduction==		==Introduction==

	~~<math>~~
	~~\text{Amperage2} =\frac{\text{Watts}}{\text{Voltage}}~~
	~~</math>~~

	Design of reliable systems is really, really hard. The main challenge is the design of reliable building blocks - i.e. circuit and board layouts - from which to create your system. Phidgets does the majority of this work for you. And, once you have reliable building blocks, designing a reliable system from them is much easier.		Design of reliable systems is really, really hard. The main challenge is the design of reliable building blocks - i.e. circuit and board layouts - from which to create your system. Phidgets does the majority of this work for you. And, once you have reliable building blocks, designing a reliable system from them is much easier.

Patrick at 15:03, 7 April 2017

2017-04-07T15:03:06Z

← Older revision		Revision as of 15:03, 7 April 2017
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	==Introduction==		==Introduction==

			<math>
			\text{Amperage2} =\frac{\text{Watts}}{\text{Voltage}}
			</math>

	Design of reliable systems is really, really hard. The main challenge is the design of reliable building blocks - i.e. circuit and board layouts - from which to create your system. Phidgets does the majority of this work for you. And, once you have reliable building blocks, designing a reliable system from them is much easier.		Design of reliable systems is really, really hard. The main challenge is the design of reliable building blocks - i.e. circuit and board layouts - from which to create your system. Phidgets does the majority of this work for you. And, once you have reliable building blocks, designing a reliable system from them is much easier.

Mparadis: /* Affected Products */

2017-04-06T19:09:42Z

Affected Products

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	Other Phidgets can be more easily used incorrectly without realizing it. These are often devices that are simple in some systems and yet complex in others. Your primary defense against designing unreliable systems is to draw the system out and identifying any problems using the concepts in this primer. To help you, however, you can generally think of two classes of Phidgets which usually need careful handling when they are part of complex systems:		Other Phidgets can be more easily used incorrectly without realizing it. These are often devices that are simple in some systems and yet complex in others. Your primary defense against designing unreliable systems is to draw the system out and identifying any problems using the concepts in this primer. To help you, however, you can generally think of two classes of Phidgets which usually need careful handling when they are part of complex systems:
	# Phidgets with more than one power source, (these can be subject to the [[#Shared Grounds\|multiple power source problems]] described above)		# Non-isolated Phidgets with more than one power source, (these can be subject to the [[#Shared Grounds\|multiple power source problems]] described above)
	# Phidgets needing precise measuring of an external power source (these can be subject to the [[#Shared Grounds\|multiple power source problems]] ''and'' [[#Precise Voltage Control\|precise voltage control]] problems)		# Non-isolated Phidgets needing precise measuring of an external power source (these can be subject to the [[#Shared Grounds\|multiple power source problems]] ''and'' [[#Precise Voltage Control\|precise voltage control]] problems)

	Expanded into individual products, the Phidgets which are most often affected are.....		Expanded into individual products, the Phidgets which are most often affected are.....

	# ~~These~~ Phidgets use a second type of external power:		# Non-isolated that Phidgets use a second type of external power:
	#* Motor controllers		#* Motor controllers
	#**{{LinksNeeded\|DC Motors and Controllers\|[[DC Motor and Controller Primer\|DC controllers]]}}		#**{{LinksNeeded\|DC Motors and Controllers\|[[DC Motor and Controller Primer\|DC controllers]]}}

Mparadis: /* How To Fix This */

2017-04-06T19:07:27Z

How To Fix This

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	The solution to all of these problems in precise voltage control systems is to use USB isolation, even for a single Phidget. The [http://www.phidgets.com/products.php?product_id=3060 3060 - USB Isolator] is one such isolator. It inserts along the USB connection between your PC and the Phidget, and it separates the Phidget (and controlled system) ground from the PC ground. This fixes ground loops, separates relative voltage mis-matches, and isolates the control system for better precision.		The solution to all of these problems in precise voltage control systems is to use USB isolation, even for a single Phidget. The [http://www.phidgets.com/products.php?product_id=3060 3060 - USB Isolator] is one such isolator. It inserts along the USB connection between your PC and the Phidget, and it separates the Phidget (and controlled system) ground from the PC ground. This fixes ground loops, separates relative voltage mis-matches, and isolates the control system for better precision.

			Again, this should be a non-issue for many Phidgets that already have isolation between the USB or VINT connector and the rest of the board. Check the description on your Phidget's product page to see if this isolation is one of its features.

	==Affected Products==		==Affected Products==