Electronics - Revision history

Leo: /* Dual Voltage Supply */

2020-09-10T18:42:38Z

Dual Voltage Supply

Leo: Text replacement - "Category:Tinkering{{Navbox Tinkering}}" to "{{Navbox Tinkering}}Category:Tinkering"

2020-06-15T00:45:24Z

Text replacement - "Category:Tinkering{{Navbox Tinkering}}" to "{{Navbox Tinkering}}Category:Tinkering"

← Older revision		Revision as of 00:45, 15 June 2020
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	[[Category:Tinkering]]~~{{Navbox Tinkering}}~~		{{Navbox Tinkering}}[[Category:Tinkering]]

Leo: /* Field-Effect Transistor */

2020-05-15T17:32:14Z

Field-Effect Transistor

← Older revision		Revision as of 17:32, 15 May 2020
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	Some useful FETs include:		Some useful FETs include:
	{\| class="wikitable"		{\| class="wikitable"
	! width="50%" N-Channel		! width="50%"\| N-Channel
	! width="50%" P-Channel		! width="50%"\| P-Channel
	\|-		\|-
	\|		\|

Leo: /* Transistors */

2020-05-15T17:30:56Z

Transistors

← Older revision		Revision as of 17:30, 15 May 2020
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	* Abs. Max <math>I_C</math>: Maximum current through collector		* Abs. Max <math>I_C</math>: Maximum current through collector
	* Abs. Max <math>V_{CEO}</math>: Maximum voltage through collector and emitter		* Abs. Max <math>V_{CEO}</math>: Maximum voltage through collector and emitter
			* Abs. Max <math>V_{CBO}</math>: Maximum voltage through collector and emitter
	* <math>V_{CE}</math>: Voltage required to turn on		* <math>V_{CE}</math>: Voltage required to turn on
	* <math>H_{fe}</math>: current gain		* <math>H_{fe}</math>: current gain
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	* <math>V_{DSS}</math>: Breakdown voltage		* <math>V_{DSS}</math>: Breakdown voltage
	* <math>R_{DS}</math>: Resistance when on		* <math>R_{DS}</math>: Resistance when on
	* Threshold <math>~~V_GS~~</math>: Minimum voltage to start turning on. Use a ~~V_GS~~ with an acceptable R_{DS} value.		* Threshold <math>V_{GS}</math>: Minimum voltage to start turning on. Use a <math>V_{GS}</math> with an acceptable <math>R_{DS}</math> value.
	\|		\|
	\|}		\|}


	Transistors come in a few different packages:		Transistors come in a few different packages:
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	\|}		\|}

			Different packages have different amounts of power dissipation. As a rule of thumb, for every degrees above 25 degrees Celsius, subtract 5 milliwatts from the maximum rating. Silicon will degrade past 150 degrees Celsius.


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	</div>		</div>
	</div>		</div>

	~~==== Important characteristics ====~~
	* <math>V_{CEO}</math> is the maximum voltage between the collector and emitter in an open circuit.
	* <math>V_{CBO}</math> is the maximum voltage between the collector and base in an open circuit.
	* <math>V_{EBO}</math> is the maximum voltage between the emitter to the base base in an open circuit.
	* <math>I_C</math> is the continuous collector current. This is the amount of power that can be dissipated by the transistor while operating in saturation mode (ie. smallest voltage drop <math>V_{CE(Sat)} * I_C</math>). If operating in any other mode, <math>V_{CE}</math> could be higher and the power generated could be higher!
	* <math>I_{CP}</math> is the pulse collector current
	* <math>h_{FE}</math> is the current gain and may be different at different voltages and collector currents.

	~~Power dissipation is the total energy that can be dissipated by the component. For every degrees above 25 degrees Celsius, subtract 5 milliwatts from the maximum rating.~~
	~~Silicon will degrade past 150 degrees celsius.~~

	=== Field-Effect Transistor ===		=== Field-Effect Transistor ===

Leo: /* Transistors */

2020-05-15T17:23:04Z

Transistors

← Older revision		Revision as of 17:23, 15 May 2020
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	== Transistors ==		== Transistors ==
	There are three types:		There are three types of transistors:
	# Bipolar Junction Transistor (BJT)		# Bipolar Junction Transistor (BJT)
	# Field-Effect Transistor (FET)		# Field-Effect Transistor (FET)
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	In short, the differences between the types are outlined in the following table.		In short, the differences between the types are outlined in the following table.
	{\| class="wikitable"		{\| class="wikitable"
	!		! !! BJT !! MOSFET !! IGBT
	! BJT
	! MOSFET
	! IGBT
	\|-		\|-
	! Cost		! Cost
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	! Current Direction		! Current Direction
	\| collector to emitter \|\| Bi-directional when on \|\| collector to emitter		\| collector to emitter \|\| Bi-directional when on \|\| collector to emitter
			\|-
			! Important Characteristics
			\|
			* Abs. Max <math>I_C</math>: Maximum current through collector
			* Abs. Max <math>V_{CEO}</math>: Maximum voltage through collector and emitter
			* <math>V_{CE}</math>: Voltage required to turn on
			* <math>H_{fe}</math>: current gain
			\|
			* Abs. Max <math>I_D</math>: Maximum current through drain
			* <math>V_{DSS}</math>: Breakdown voltage
			* <math>R_{DS}</math>: Resistance when on
			* Threshold <math>V_GS</math>: Minimum voltage to start turning on. Use a V_GS with an acceptable R_{DS} value.
			\|
	\|}		\|}

Leo: /* Transistors */

2020-05-15T16:46:16Z

Transistors

@@ Line 52: / Line 52: @@
 == Transistors ==
-There are two types: Bipolar Junction Transistor (BJT) and Field-Effect Transistor (FET).  BJT controls current by the current through in the base by the gain. FET controls current by the voltage in the gate.
+There are three types:
 Transistors come in a few different packages:

Leo: /* Operational Amplifiers */

2020-05-13T03:57:18Z

Operational Amplifiers

← Older revision		Revision as of 03:57, 13 May 2020
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	* Input offset current is the amount of current flowing into each of the input terminals in order to bias the internal transistors. Ideally this should be 0A. A LM358 has 20 nanoamps.		* Input offset current is the amount of current flowing into each of the input terminals in order to bias the internal transistors. Ideally this should be 0A. A LM358 has 20 nanoamps.

			Additional example uses here: https://www.arrow.com/en/research-and-events/articles/fundamentals-of-op-amp-circuits

	=== Inverting Op-Amp Circuit ===		=== Inverting Op-Amp Circuit ===

Leo: /* Non-Inverting Op-Amp */

2020-05-13T03:32:15Z

Non-Inverting Op-Amp

← Older revision		Revision as of 03:32, 13 May 2020
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	<div class="col-lg-4">'''Summation Op-Amp Circuit'''		<div class="col-lg-4">'''Summation Op-Amp Circuit'''
	The summer adds all voltages. Inputs can be weighed based on the input resistor.		The summer adds all voltages. Inputs can be weighed based on the input resistor.
	[[File:Non-Inverting Op-Amp Summer.svg~~\|thumb~~\|center]]		[[File:Non-Inverting Op-Amp Summer.svg\|center]]
	</div>		</div>
	</div>		</div>

Leo: /* Non-Inverting Op-Amp */

2020-05-13T03:31:52Z

Non-Inverting Op-Amp

← Older revision		Revision as of 03:31, 13 May 2020
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	A non-inverting op-amp circuit is identical to the inverting op-amp circuit with the difference being the input is now applied to the positive input.		A non-inverting op-amp circuit is identical to the inverting op-amp circuit with the difference being the input is now applied to the positive input.
	[[File:Non-Inverting Op-Amp.svg\|center]]		[[File:Non-Inverting Op-Amp.svg\|center]]

			The input in a non-inverting op-amp circuit is not inverted. The bias is also different because our input is no longer directly going into the feedback loop. Other example configurations are given below.

	<div class="row">		<div class="row">
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	</div>		</div>
	</div>		</div>


	=== Example Components ===		=== Example Components ===

Leo: /* Operational Amplifiers */

2020-05-13T03:28:40Z

Operational Amplifiers

← Older revision		Revision as of 03:28, 13 May 2020
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	It turns out that a inverting op-amp's output ends up being <math>v_O = -\frac{R_2}{R_1}v_i</math>. Despite having an infinite bias, this circuit's use of negative feedback allows us to precisely control its output gain.		It turns out that a inverting op-amp's output ends up being <math>v_O = -\frac{R_2}{R_1}v_i</math>. Despite having an infinite bias, this circuit's use of negative feedback allows us to precisely control its output gain.

	<div class="row"~~><!-- don't want toc for these headers --~~>		<div class="row">
	<div class="col-lg-4">'''Basic Op-Amp Circuit'''		<div class="col-lg-4">'''Basic Op-Amp Circuit'''
	The inverting op-amp where the output is inverted and adjusted by the two resistors.		The inverting op-amp where the output is inverted and adjusted by the two resistors.
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	</div>		</div>

	=== Non-Inverting ===		=== Non-Inverting Op-Amp ===
	A non-inverting op-amp circuit is identical to the inverting op-amp circuit ~~above but~~ the input is ~~connected~~ to the positive ~~input rather than negative. The negative feedback loop is still preserved by connecting the output to the negative~~ input.		A non-inverting op-amp circuit is identical to the inverting op-amp circuit with the difference being the input is now applied to the positive input.
	* The negative input is connected to ground rather than the input.		[[File:Non-Inverting Op-Amp.svg\|center]]
	* The positive input is connected to the input.

	~~Like the inverting configuration, this circuit also has a feedback loop~~		<div class="row">
	An alternative circuit would be to have the output connect directly to the negative input which is known as a buffer. Any positive input will be repeated by the output. Buffers are useful when we need to read a voltage without disturbing it.		<div class="col-lg-4">'''Voltage Follower / Buffer'''
			The output follows the input and is also known as a buffer or unity gain.
	=== Buffer ~~Signal ===~~		[[File:Non-Inverting Op-Amp Follower.svg\|center]]</div>
	~~Simplest closed-loop op-amp circuit, where the~~ output ~~is tied to~~ the ~~negative inverting~~ input ~~terminal. This creates a voltage follower~~ and ~~effectively makes the op-amp have a gain of 1,~~ also known as a unity gain. ~~Signals passed through this circuit are neither amplified or attenuated~~.		<div class="col-lg-4">'''Summation Op-Amp Circuit'''
			The summer adds all voltages. Inputs can be weighed based on the input resistor.
	The ~~use for this is to buffer the signal between to different circuits~~. ~~This is done because the impedance between~~ the input ~~and output are different. The input impedance is low, but the impedance in the output is high~~.		[[File:Non-Inverting Op-Amp Summer.svg\|thumb\|center]]
			</div>
			</div>
	~~An example op~~-~~amp is the 741 which contains only one op~~-~~amp in the 8-pin PDIP package. A 358 has 2 op-amps~~.

	An op-amp functions as a differential amplifier with the output voltage equal to the difference of the non-inverting input and the inverting input voltage, multiplied by the open-loop gain (<math>A_{OL}</math>). Op-amps are designed to have a large open-loop gain, typically over 100,000.

	~~<math>V_{OUT}~~ = ~~A_{OL}(V_+~~-V_-~~)</math>~~		=== Example Components ===
			An example op-amp is the LM741 which contains only one op-amp in the 8-pin PDIP package.

	~~When an op-amp~~ is ~~used like~~ a ~~comparator~~, ~~it is in the open-loop configuration. Using an~~ op-amp ~~in an open-loop configuration makes it very easy to saturate the op-amp because a tiny voltage difference between the input pins will yield a very large change in the output~~.		A LM358 is a low cost, low power, a dual op-amp.

	~~To reduce the sensitivity, a closed-loop configuration can be used where the op-amp's output is feed back to one of the input in order to stabilize itself.~~

	~~Negative Feedback: When the feedback is routed to the inverting input (negative). Output counteracts changes to input, and lets the circuit achieve equilibrium.~~

	~~Positive Feedback: Feedback is routed to the non-inverting input (positive). The output quickly goes into one of two states: Saturating at the positive or negative supply rail value. Less common.~~

	~~LM358: Low cost, low power, a dual op-amp.~~

	=== Characteristics ===		=== Characteristics ===
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	This acts as a 1-bit analog to digital converter.		This acts as a 1-bit analog to digital converter.


	=== Dual Voltage Supply ===		=== Dual Voltage Supply ===
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	~~=== Non-Inverting Amplifier ===~~

	~~Connect the op-amp's output through a resistor <math>R_f</math>~~
	~~and ground through another resistor <math>R_2</math>~~
	~~to the negative inverting input terminal with.~~

	~~The non-inverting input terminal is connected to <math>V_{in}</math>.~~

	~~<math>\text{Voltage Gain} = 1 + \frac{R_f}{R_2}</math>~~

	~~It is not possible to build a non-inverting amplifier circuit with a gain less than 1.~~

	[[Category:Tinkering]]{{Navbox Tinkering}}		[[Category:Tinkering]]{{Navbox Tinkering}}