Reading Schematics (Circuit Diagrams) Part 1.Schematics (USA) or Circuit Diagrams (UK & Ireland) are 2 dimensional drawings of a physical Electronic circuit that can be more than one part and on more than one layer. In this sense it’s a bit like the idea of Architectural plans for a Building, Engineering Drawing of mechanical part or assembly or even the map of a transportation system like the London Underground.The Electronic schematic or Circuit Diagram is in some ways simpler. Each symbol represents an electronic component in a Logical sense (not its appearance) like the circle for a Station on the London Underground.Innovation: London Underground map 1933Note that the Underground map only shows the interconnections and relationships of the stations. It’s not remotely to scale and only vaguely geographic.
Vacuum tube diagram. Electronic Tube SymbolsAdherence to Fundamental Principles Prevents Costly MistakesBy Carl E. 1 - Standard methods of. UNIT SIX Vacuum Tubes OBJECTIVES: After completing this unit, you will be able to: O State a few applications where vacuum tubes have not yet been.
The lines are the connections between stations, these are actually railway tracks, but the length isn’t really important. Before 1933 the Underground Map was drawn like a real map, not a schematic as above!London Underground map 1932In the earliest days of Electronics in the 19 th Century and sometimes even up to the 1960s circuits were often drawn as simplified diagrams of the Illustration type, in the sense of the 1932 map.fig1. Camm’s diagram for Beginners in 1956!fig 2.
The same radio shown as “Theoretical Circuit”fig 3. Another style by F. Camm 1956Here is a modern European style circuit:fig. 4 European StyleThe lines are representing wires. The schematic doesn’t tell you if they are really wires, stranded, solid, tag strip connections (D1, C7, R5 and TR2 might not be connected to wires but all soldered to a common “tag” insulated from the chassis). Or the connections could be printed circuit tracks.
It’s not normally important. The “thick” line represents Zero Volts, or “Earth” or 0V or “Ground” or “Common” or Chassis. It’s just indicating that these parts are all connected to each other. Sometimes the thick line might mean the connection (connecting wire) is via the low resistance of the metal chassis or a dedicated layer on a PCB (Printed Circuit Board).You’ll notice on F. Camm’s Circuit Diagram some little hoops. This means the wires cross without electrical connection. He shows connections to a wire by a dot, like a blob of solder!Anyone experienced will immediately actually spot what fig 4.
Actually does (if you do, you don’t really need this article!) and possibly what the application is, even if they have never seen it before, because not only does it use standard symbols, but it follows common layout conventions too such as input on left, power at top, 0V or ground/common at the bottom., the orientation of TR2 2N2222A and the output on the right. Sometimes these conventions are validly ignored in more complex circuits.Step by Step. Symbols from 1921 to 2012Wires (connections between parts)fig 6. Wire connections.A connection between 2 or more parts.A junction of two wires connecting.Four wires connecting. Only 3b and 3C are used today as 3 and 3a are ambiguous. The “dot” on 3a can vanish on copies.Two wires crossing.
4b is less common now as only 3b & 3c are used generally.It’s possible to see 3 & 4 on the same 1940s diagram. Only context (understanding the circuit) reveals if it’s four wires connecting or two wires crossing and not connected. When drawing by hand only use 3b or 3c for connections and only 4b for unconnected wires crossing. On CAD / CAE it’s acceptable to use 4, only use 3b or 3c for four wires connecting!ResistorsResistors and coils can be confused!The current is always I = V/R. If R is kilo Ohms, Current is mA (milli-amps). If R is Mega Ohms the current is in uA (micro-amps).
If you have 10,000V and 1K the current is 10,000mA = 10 AmpsPower rating needed is always I 2 x R We often use. for multiply so Power in Watts is P = I 2.R.
The power is also P = V 2/R Usually the power is only marked if larger than normal. By default ¼ Watt resistors are common.fig 7. Resistor symbols.Vintage style, early 1900s.US and UK style.European mainland style (Also Philips in UK)Resistors were initially only low value wire coils. Grid leak resistors then added as carbon in glass fuse like holders. Most resistors (not surface mount) are cylindrical with axial wires, looking like symbol “3” from the side.Wires are actually just very low value resistors, and resistors are like wires that are a poor connection (a high resistance to current flow).
Even if power limit isn’t exceeded, the very high value resistors may not be able to dissipate full power due to voltage rating. Similarly low value resistors have a maximum pulse voltage (can be 200V on smaller parts) even if average power isn’t exceeded.Coils A.K.A. InductorsCoils are simply longer wires. If they are coiled up the inductance increases, often proportional to N 2 where N is the number of turns in the coil. An old name for the Inductor is “Choke” when it is to block mains hum or RF rather than part of a tuned cicuit.fig 8. Coil or Inductor or Choke symbols.Vintage coil symbol.US & UK traditional symbol.Mainland European symbolA plain inductor symbol often means the coil has air core.
Higher value inductors may use iron dust or ferrite core to increase inductance. Such cores are not conductive, hence rows of dashes (2a). There are various patterns in the box or the dashed lines like US/UK coil on the European symbol. At lower frequencies such as mains or audio the core may be sheets of steel to increase the inductance, hence the parallel line symbols (2b). If the core was solid it would act like a huge number of short circuited turns.
It’s not uncommon to see a schematic use US/UK coil symbols but European resistor symbols.A perfect Inductor has no effect on a steady DC current no matter what inductance it has. As the current changes faster the Inductor has more effect in the circuit.
See Basic Electronics.CapacitorsThese are essentially two wires that are insulated from each other. The simplest method is two plates with a thin insulation to isolate them of air, vacuum, oiled paper, waxed paper, aluminium oxide, mica (a natural transparent mineral), ceramic or plastic. This is reflected in the symbolsfig 9. Various capacitorsAn old name for a capacitor is a Condenser. The + and -symbols for polarity are not often shown on the schematic. Sometimes any of the first four symbols are used with a + to indicate polarity.
To get more capacitance in a small space the capacitor can be constructed of two foils offset slightly on a thin flexible insulator and wound to make a cylinder. One wire can be in the centre and the other clamped to the outside to make the two wires exit at same end (Radial), or the wires can be pressed against pressed down foil where it sticks past the insulator, giving axial connections at opposite ends. Even if the capacitor isn’t polarised, one side is thus an “outer” and can screen the part if that side is regarded as earthy. This can be indicated on the case.
Paper, Mica, plastic, air, vacuum and ceramic insulators (dielectric material) are not inherently polarised so the capacitor can connect to AC or DC at any way round. Aluminium or Tantalum based capacitors and all “Electrolytic” capacitors have a special conductive liquid. One sheet or side of the capacitor has a very thin film of oxide formed by reaction with the liquid in vintage parts or on modern parts merely maintained by the liquid. If the DC voltage was reversed the film would dissolve and the part catastrophically fail (explosion and/or fire is possible). So correct polarity (+ & -) connection must be observed on replacement. Paper insulation may only last 15 years.
Mica virtually forever unless physically damagedBatteries Switches and LampsLamps can also be called Bulbs or Indicators.fig 10. Lamps, switches, cell and batteries.Two common bulb/lamp symbols.2a is normally open (off: push to make) and 2b is normally closed (on: push to break). 2c and 2d are alternate styles.A single cell (3a or 3b). No common cell is actually 1.5V, that’s a nominal value. A battery is a collection of cells (3b, 3c or 3d).There are very many symbols for switches. In the next part we will “decode” some German Radio push button arrays.This article was edited 19.Mar.12 20:44 by Michael Watterson. In 1941 Camm presents the following symbols in 'Camm, F.J.: Practical Wireless Service Manual, 3rd ed.
Georges Newnes Ltd., London, 1941'In Germany, different symbols were used.In the book 'Handbuch der Funktechnik und ihrer Grenzgebiete, Bd. 9; Fortschritte der Funktechnik, Bd. 6, Franckh, Stuttgart, 1941' the following symbols are shown.Please note: there is a change in norming the symbols by 1941.Especially, the battery symbol was reversed (!), which should be kept in mind.Hopefully, these symbols will help understanding pre war German schematics.This article was edited 19.Mar.12 18:29 by Dietmar Rudolph. Google theverge.com/2012/9//tube-map-radio-yuri-suzukiQuoted extractThe famous design of the London Underground map was first conceived in the 1930s by engineering draftsman Harry Beck, who based his idea around the clarity and simplicity of electrical schematics — now, Japanese designer Yuri Suzuki has taken the concept full circle, creating a functioning radio using the Tube map as a circuit board.
Fifa 19 pc spanish commentary. Download FIFA 19 Language Pack Commentary Files For PC. This is commentary language files for FIFA 2019 / FIFA 19 PC, you can download from single link. Availabe commentary: Arabic, Brazilian, English, French, German / Deutsch, Italian, Japanese, Mexican, Netherlands / Dutch, Polish, Russian, Spanish.
Save game digimon world data squad. Currently on display at London's Design Museum, the printed circuit board (PCB) covers the full length and breadth of the city's present-day transport network, using strategically placed resistors, capacitors and other electrical components to harness the interconnections in the system.' I think the PCB is a remarkable invention,' says Suzuki in an explanatory video.
'Due to the process and efficiency of the electronics, you can see a really complex maze.' His radio makes use of all 11 of the London Underground's lines, as well as the Overground and the Docklands Light Railway (DLR) — it even incorporates the Emirates Air Line, the new cable car system that runs 295 feet above the Thames in East London.Google for article to see large photoThis article was edited 17.Sep.12 15:01 by Michael Watterson.
The above image is an early test using a 12AX7, as the B+ capacitor discharges at 10 volt intervals the bias is stepped (in the case above 0v,.5V, -1V, -1.5V, -2V, -2.5V,.3V) and current readings taken, the entire set of curves are produced in one capacitor discharge. Improvements have been made since this trace was taken, I shall do some more and post them soon.A grid stopper cleaned things up a lot, the data is collected 100us after setting the grid voltage. BTW The B+ discharge capacitor is 110uF. 19 September 2014. A used but quite good EL34. The maximum negative grid bias can be a limitation with power tubes. 243 data points taken by the tester and used to produce this chart in open office.
This seems to be a good test of power tubes, it is easy to spot weak tubes, It will be noted some data points were collected at greater than the tubes maximum dissipation rating, the measurements are taken so fast the temperature rise in the anode is minimal, as stated previously the entire test uses the equivalent power of less than 5 watts for one second. The 0 to 300V (x axis) scale, the 0 to 300mA (y axis) and the bias voltage legend to the right of the chart are generated automatically by Open Office or Excel. Simply import the data and create a scatter graph. Primary Objectives of this project:1/ To build a simple to use device thatwould enable non technical people to test the most common tubes used in the typeof tube amplifiers used by musicians.2/ To provide some idea of the tubesremaining life and to provide some tube matching information, it is assumed the tube works.3/ Have the device powered from 12volts DC.4/ The device must work in a standalone mode, i.e. No phone, PC or tablet required.5/ If possible using a Bluetoothconnection export data to a PC, Bluetooth proposed and not hard wiring for safety reasons.6/ Have no continuous high voltagespresent, the device is to use a capacitor designed for use in a smallxenon camera flash, it is charged just prior to a test and discharged duringthe test.7/ Require no special software toimport data to PC.
Bluetooth serial port with ASCI pre formatted foreasy import to any spreadsheet.8/ Use triode connection of pentodesand beam tetrodes, if a tube won't perform in triode connection itcannot perform in pentode connection.9/ Use a simple, select tube and pressthe start button to test and display on the inbuilt LCD transconductance, plate resistance and the percentage of new tube trans-conductance. Further pressing of the start button to display,amplification factor, anode current, bias voltage, test voltage andthe raw data readings. A Bluetooth broadcast of basic test result tooccur.10/ Within the limits of the availableB+ voltage (300V) and bias voltage (-25V) the device will export a set of triodecurves, this output only sends formatted data to Bluetooth nothing on LCD.11/ Be electronically robust andwithstand a anode to cathode short when the start/test button ispushed.12/ Be able to test tubes at maximumdissipation while limiting the absolute power used per test to. Two high-side FET switches that will safely handle a anode to cathode short when the 110uF cap is switched to the circuit under test, harder to make satisfactory was flash-over protection just after the FET switched on, early tests showed a 250mA fuse would go off like a flash lamp and blow the FET, the circuit can now handle the fast current rise time and the fuse is not required. Thank goodness for spice simulations, an actual test circuit was short circuited about 25 times with 350V on the low ESR capacitor, BTW 300V used for actual testing of tubes. A firmware controlled linear heater supply.
As a 5 bit DAC was available, 220mV steps are used, the series pass transistor is a TO-247 to lower the thermal resistance to the aluminum case. The heater current is now rated at 1.6 amps (KT88, 6550A) and is short circuit proof. A linear supply is used as it is very low noise. Series pass transistor dissipation will be. The new software adjustable heater supply works well and has a current limit of 2 amps.The new negative bias generator easily generates 40 volts and the design will allow it to do twice that voltage with some component changes, as expected some interference is produced as it employes one inductor (the first one was inductor less), testing will confirm if it needs to be off when measurements are made, at the moment it has an unshielded coil and the B field is detectable. The E field should not be a problem.
Above is an image of the new board under test, the series pass transistor on the heatsink will be soldered directly on the PCB and thermally coupled via an aluminum block to the die-cast aluminum case. The ribbon cable exiting to the right of the image goes to the start and stop buttons and the potentiometer with the chicken head knob. Note extensive use of 2512 resistors. The plug in board at the top is for Bluetooth. None of the TO-220 devices get warm, they are used as are a small footprint and very economical, IRF840's are used for the B+ generator and for the two high-side switches. Still missing the high voltage SOT-23's for the short circuit protection so the shorted tube test has not been performed.
I will again change the micro again as they seem to grow in power and memory size by the day with no increase in cost. The cry from potential customers is. Just get it on the market!6 November 2019I'm back!This project has beenterminated as it was found that pulse testing can make weak tubeslook better than they actually are; running the heater for a coupleminutes then burst testing makes the emission lookbetter than it actually is.It was also found thegrid current on some tubes passed a pulse test and subsequentlyfailed after running 10 minutes at near maximum dissipation. I have started work ona stand alone micropressor tube tester that can run tubescontinuously at full power, it uses a receipt printer to print afull report.