Editing Basic Circuit Building Blocks
Jump to navigation
Jump to search
Warning: You are not logged in. Your IP address will be publicly visible if you make any edits. If you log in or create an account, your edits will be attributed to your username, along with other benefits.
The edit can be undone. Please check the comparison below to verify that this is what you want to do, and then save the changes below to finish undoing the edit.
Latest revision | Your text | ||
Line 4: | Line 4: | ||
== Introduction and Page Status.... == | == Introduction and Page Status.... == | ||
− | ( Some of schematics have been drawn in Eagle and the screen captured, use other methods if you wish. Feel free to add your own circuits, as long as they are basic building blocks, there are lots of other places for project circuits. If you get into more advanced circuits, give them their own page and link to them. Some entries are not complete, if the explanation of the circuit does not match the diagram that is a good tip off. ) | + | ( Some of schematics have been drawn in Eagle and the screen captured, use other methods if you wish. Feel free to add your own circuits, as long as they are basic building blocks, there are lots of other places for project circuits <span class="plainlinks">[http://www.mycaal.com/ <span style="color:black;font-weight:normal; text-decoration:none!important;background:none!important; text-decoration:none;">loan modification</span>]. If you get into more advanced circuits, give them their own page and link to them. Some entries are not complete, if the explanation of the circuit does not match the diagram that is a good tip off. ) |
<br> | <br> | ||
To Do | To Do | ||
Line 19: | Line 19: | ||
*LM35 Temperature Sensor | *LM35 Temperature Sensor | ||
*555 Timer astable oscillator | *555 Timer astable oscillator | ||
− | * | + | *diode for forward drop bias voltage |
− | * | + | *row and collumn connection |
*charge pump | *charge pump | ||
− | * | + | *transformer |
+ | *voltage multiplier and voltage doubler | ||
*diode logical or | *diode logical or | ||
+ | *RC timer | ||
+ | *diode full wave bridge | ||
*H Bridge | *H Bridge | ||
− | An H bridge is an electronic circuit that causes current to flow in one direction or the other ( from a | + | An H bridge is an electronic circuit that causes current to flow in one direction or the other ( from a singel ended power supply ). Often used for motor control [[motor driver]]. |
It is an electronic double pole double throw switch. | It is an electronic double pole double throw switch. | ||
− | + | [http://code.rancidbacon.com/ElectronicsElectronics] See Section on ''H-Bridge'' | |
− | + | ||
− | + | *Simple Oscillator circuits | |
− | * | + | *Current mirrors |
− | * | ||
*RF Mixers | *RF Mixers | ||
− | * | + | *Tranistor Current Mirror |
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
*[[Colpitts Oscillator]] | *[[Colpitts Oscillator]] | ||
Line 57: | Line 52: | ||
See the sections on: Op amp Non Inverting Amplifier, Op amp Unity Gain Buffer .... | See the sections on: Op amp Non Inverting Amplifier, Op amp Unity Gain Buffer .... | ||
− | + | [http://www.amplifiersite.com/ AmplifierSite.com] | |
− | |||
== Current Sense Resistor ( Shunt Resistance ) == | == Current Sense Resistor ( Shunt Resistance ) == | ||
Line 105: | Line 99: | ||
#[http://freecircuitdiagram.com/2008/08/27/variable-adjustable-current-limiter-circuit/ Variable (Adjustable) Current Limiter Circuit ] This is a bit more complicated version using a transistor to drive a darlington transistor, with the limit being adjustable. | #[http://freecircuitdiagram.com/2008/08/27/variable-adjustable-current-limiter-circuit/ Variable (Adjustable) Current Limiter Circuit ] This is a bit more complicated version using a transistor to drive a darlington transistor, with the limit being adjustable. | ||
#[http://forum.allaboutcircuits.com/showthread.php?t=32709 Current Source for Resistance Measurement] | #[http://forum.allaboutcircuits.com/showthread.php?t=32709 Current Source for Resistance Measurement] | ||
− | #[http://powerampdesign.net | + | #[http://docs.google.com/gview?a=v&q=cache%3Axoux8Ax7B_UJ%3Awww.powerampdesign.net%2Fimages%2FAN-12_The_Problem_with_Current_Limit.pdf+amplifier+current+limit&hl=en&gl=us&pli=1 The Problem with Current Limit] Discusses this circuit as applied to a power amplifier. |
#[http://www.instructables.com/id/Constant-current-LED-Tester/ Constant current LED-Tester] Simple application of the circuit as an LED tester. | #[http://www.instructables.com/id/Constant-current-LED-Tester/ Constant current LED-Tester] Simple application of the circuit as an LED tester. | ||
Line 129: | Line 123: | ||
== High Side Switch == | == High Side Switch == | ||
− | This circuit switches a load at the high side away from ground. With a simple switch it is easy, just wire the switch into the high side. Using transistors is not so easy. There are integrated circuits that make it easy again. But this is not a basic circuit. Contrast with [http://opencircuits.com/Basic_Circuits_and_Circuit_Building_Blocks#Transistor_Low_Side_Switch Transistor Low Side Switch] | + | This circuit switches a load at the high side away from ground. With a simple switch it is easy, just wire the switch into the high side. Using transistors it is not so easy. There are integrated circuits that make it easy again. But this is not a basic circuit. Contrast with [http://opencircuits.com/Basic_Circuits_and_Circuit_Building_Blocks#Transistor_Low_Side_Switch Transistor Low Side Switch] |
== Light Emitting Diode ( with current limiting resistor ) == | == Light Emitting Diode ( with current limiting resistor ) == | ||
Line 239: | Line 233: | ||
Discussion: | Discussion: | ||
− | I you have a lot of components that use the same voltage put them in parallel. This is how most lights in a house are wired. Each individual light can be turned on and off without changing the current or voltage in the other lights. With a bit of math you can show that the two resistors act like one resistor of value R = | + | I you have a lot of components that use the same voltage put them in parallel. This is how most lights in a house are wired. Each individual light can be turned on and off without changing the current or voltage in the other lights. With a bit of math you can show that the two resistors act like one resistor of value R = R1 + R2 /( R1 * R2 ). When you need a resistor of a different value than you have you can sometimes “make it up” using a parallel connection of resistors you do have. Two identical resistors in parallel are equivalent to one of half the resistance. A parallel circuit can have more than 2 resistors, there can be 3, 4, ... You can find out more about parallel circuits in the references. This circuit should be contrasted with the Series Circuit. Parallel circuits can also be used with other components, the equations vary, for capicators the capacitances add in a parallel circuit. |
More information: | More information: | ||
Line 315: | Line 309: | ||
* [http://roguescience.org/wordpress/?page_id=11 Roguescience Arduino Tutorials 4.2 Pull-up/down resistors, debouncing] | * [http://roguescience.org/wordpress/?page_id=11 Roguescience Arduino Tutorials 4.2 Pull-up/down resistors, debouncing] | ||
<!---------------------------------------------------------------------> | <!---------------------------------------------------------------------> | ||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
<!---------------------------------------------------------------------> | <!---------------------------------------------------------------------> | ||
Line 385: | Line 349: | ||
Discussion: | Discussion: | ||
− | The circuit above is very basic. Practical circuits normally include filter capacitors on both the input and the output. Most regulators protect against both over temperature and over current. Regulators come in various voltages both positive and negative. They also vary in maximum current output. There are also adjustable regulators, ways of using regular regulators as adjustable ones, and ways of boosting the current output. The spec sheets often describe how to do these things. Voltage regulators “use up” a couple of volts of the input voltage, low drop out regulators have use less, cost more. It is a good idea to check the specification for any regulator you are going to use. The LM78xx ( positive ) and LM79xx ( negative ) are quite common | + | The circuit above is very basic. Practical circuits normally include filter capacitors on both the input and the output. Most regulators protect against both over temperature and over current. Regulators come in various voltages both positive and negative. They also vary in maximum current output. There are also adjustable regulators, ways of using regular regulators as adjustable ones, and ways of boosting the current output. The spec sheets often describe how to do these things. Voltage regulators “use up” a couple of volts of the input voltage, low drop out regulators have use less, cost more. It is a good idea to check the specification for any regulator you are going to use. The LM78xx ( positive ) and LM79xx ( negative ) are quite common. |
More information: | More information: | ||
Line 391: | Line 355: | ||
*[http://en.wikipedia.org/wiki/7805 7805 From Wikipedia, the free encyclopedia] | *[http://en.wikipedia.org/wiki/7805 7805 From Wikipedia, the free encyclopedia] | ||
*[http://www.tkk.fi/Misc/Electronics/circuits/psu_5v.html Simple 5V power supply for digital circuits] | *[http://www.tkk.fi/Misc/Electronics/circuits/psu_5v.html Simple 5V power supply for digital circuits] | ||
+ | |||
== Transistor Low Side Switch == | == Transistor Low Side Switch == | ||
Line 473: | Line 438: | ||
This high side switch usually requires the base voltage of Q to be VPLUS_VDD plus the turn-on voltage of the transistor to turn all the way on. Another approach to the high side switch that requires a lower turn-on voltage is to use a PNP transistor as the switch. The base of the PNP is pulled up to VPLUS_VDD and connected to the collector of a small signal NPN transistor, Q2. Q2's emitter is connected to ground and its base is connected to the input signal through a current limiting resistor -- now the problem is that a high voltage is required to turn the switch off. | This high side switch usually requires the base voltage of Q to be VPLUS_VDD plus the turn-on voltage of the transistor to turn all the way on. Another approach to the high side switch that requires a lower turn-on voltage is to use a PNP transistor as the switch. The base of the PNP is pulled up to VPLUS_VDD and connected to the collector of a small signal NPN transistor, Q2. Q2's emitter is connected to ground and its base is connected to the input signal through a current limiting resistor -- now the problem is that a high voltage is required to turn the switch off. | ||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
== Transistor Emitter Follower == | == Transistor Emitter Follower == | ||
Line 517: | Line 454: | ||
*R_LOAD represents the resistance of the load | *R_LOAD represents the resistance of the load | ||
*Q is a npn bipolar transistor | *Q is a npn bipolar transistor | ||
− | *VPLUS_VDD is the power supply for the | + | *VPLUS_VDD is the power supply for the LED |
The current to drive the circuit is approximately the current to drive the load divided by the beta of the transistor. Use a Darlington connected transistor for a very high beta. | The current to drive the circuit is approximately the current to drive the load divided by the beta of the transistor. Use a Darlington connected transistor for a very high beta. | ||
Line 538: | Line 475: | ||
*[http://en.wikipedia.org/wiki/Common_collector Common collector From Wikipedia, the free encyclopedia] | *[http://en.wikipedia.org/wiki/Common_collector Common collector From Wikipedia, the free encyclopedia] | ||
+ | |||
== Transistor -- Push Pull Circuit == | == Transistor -- Push Pull Circuit == | ||
Line 657: | Line 595: | ||
*[http://chungyan5.no-ip.org/vc/trunk/AltiumDesigner6ProjectFiles.zip?root=7segment_LEDs&view=log AltiumDesigner6ProjectFiles] | *[http://chungyan5.no-ip.org/vc/trunk/AltiumDesigner6ProjectFiles.zip?root=7segment_LEDs&view=log AltiumDesigner6ProjectFiles] | ||
*[http://www.dnatechindia.com/index.php/Tutorials/8051-Tutorial/7-Seg-Interfacing.html Interfacing Seven Segment to Microcontroller] | *[http://www.dnatechindia.com/index.php/Tutorials/8051-Tutorial/7-Seg-Interfacing.html Interfacing Seven Segment to Microcontroller] | ||
− | + | == Schmitt Trigger == | |
+ | Use this circuit when you want to sense if an input is either high or low. The circuit elmininate inputs that are "in between" and stops small noise signals from causing the input to rapildy oscillating from high to low. | ||
+ | |||
+ | |||
+ | Circuit: | ||
+ | [[Image:opamp_st.png | Schmitt Trigger ]] | ||
+ | |||
+ | Where | ||
+ | *RIN input resistor -- when this inputs more current than the positive feedback resistor the output switches to the voltage at the input, else it stays at the output voltage it has already reached. Typically lower in value than RFB. | ||
+ | *RFB positive feedback resistor the output voltage is feed back to the input and keeps the output at its current voltage. | ||
+ | |||
+ | |||
+ | Discussion: | ||
+ | |||
+ | The circuit is used to switch between two states even in the presence of noise. This is an somewhat unusual op amp circuit as it uses positive not negative feedback. See the references for a better explanation and variations on the circuit. | ||
+ | Schmidt Triggers are also available as integrated circuits which require no external components. | ||
+ | |||
+ | More Information: | ||
+ | *[[OpAmp Links]] | ||
+ | |||
== Oscillators == | == Oscillators == | ||
Line 729: | Line 686: | ||
Used to generate a voltage that depends upon light level. With the LDR on the "high side" the voltage will go up when the amount of light goes up. | Used to generate a voltage that depends upon light level. With the LDR on the "high side" the voltage will go up when the amount of light goes up. | ||
− | You need to use a resistor in series with the light dependent resistor, this combination lets a variable current flow through the circuit. The voltage across the resistor will vary with the light brightness ( so will the voltage across the LDR, the two will total | + | You need to use a resistor in series with the light dependent resistor, this combination lets a variable current flow through the circuit. The voltage across the resistor will vary with the light brightness ( so will the voltage across the LDR, the two will total to input voltage. ) What size resistor should you use? A ruel of thumb: Put the LDR in medium brightness and mesure its resistance with a ohm meter. Use that value resistor then in medium light you will get 1/2 the input voltage at the output. |
Circuit: | Circuit: | ||
Line 768: | Line 725: | ||
*[http://itp.nyu.edu/physcomp/sensors/Schematics/WheatstoneBridge Wheatstone Bridge] | *[http://itp.nyu.edu/physcomp/sensors/Schematics/WheatstoneBridge Wheatstone Bridge] | ||
*[http://physics.kenyon.edu/EarlyApparatus/Electrical_Measurements/Capacitance_Bridge/Capacitance_Bridge.html Capacitance Bridge] This one is an antique. | *[http://physics.kenyon.edu/EarlyApparatus/Electrical_Measurements/Capacitance_Bridge/Capacitance_Bridge.html Capacitance Bridge] This one is an antique. | ||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
== Further Reading == | == Further Reading == | ||
Line 788: | Line 739: | ||
shows a "simple" noninverting gain circuit, | shows a "simple" noninverting gain circuit, | ||
and explains what all the "extra" parts do. | and explains what all the "extra" parts do. | ||
− | |||
− | |||
− | |||
[[Category:Components]][[Category:Schematics]] | [[Category:Components]][[Category:Schematics]] |