Electronic Product Design involves Electrical, Mechanical and Material Engineering too. This depends on the product complexity and the involvement of the R&D team in the component engineering too. Some products like RF and Robotics may need custom semiconductors and Some Wearable Electronics may need a custom ASIC as the heart of the device.
Circuit Design Service of delabs - Product and Circuit design. Consulting tech service.
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These voltage regulators are monolithic integrated circuits designed as fixed−voltage regulators for a wide variety of applications including local, on−card regulation. These regulators employ internal current limiting, thermal shutdown, and safe−area compensation.
With adequate heatsinking they can deliver output currents in excess of 1.0 A. Although designed primarily as a fixed voltage regulator, these devices can be used with external components to obtain adjustable voltages and current
Standard Voltages are - 5V - 6V - 8V - 9V - 12V - 15V - 18V - 24V
The MC7900 series of fixed output negative voltage regulators are intended as complements to the popular MC7800 series devices. These negative regulators are available in the same seven voltage options as the MC7800 devices.
Common ground is required between the input and the output voltages. The input voltage must remain typically 2.0 V above more negative even during the high point of the input ripple voltage.
All above circuits can be adapted to the negative 7900 regulators circuits. You have to remember PNP transistors are not used in the final output stages. NPN can take the heat and current loads. So it makes your Negative Regulator Boosters a bit complex. The below two circuits have the 7900 regulators playing their negative roles.
When a boost transistor is used, short circuit currents are equal to the sum of the series pass and regulator limits, which are measured at 3.2 A and 1.8 A respectively in this case. Series pass limiting is approximately equal to 0.6 V/RSC. Operation beyond this point to the peak current capability of the MC7905C is possible if the regulator is mounted on a heatsink; otherwise thermal shutdown will occur when the additional load current is picked up by the regulator.
The MC7815 and MC7915 positive and negative regulators may be connected as shown to obtain a dual power supply for operational amplifiers. A clamp diode should be used at the output of the MC7815 to prevent potential latch−up problems whenever the output of the positive regulator (MC7815) is drawn below ground with an
output current greater than 200 mA.
The ADXL345 from Analog Devices is a small, thin, low power, 3-axis accelerometer with high resolution 13-bit measurement at up to ±16 g.
Ben's HobbyCorner - Software - Bascom-examples On the right the ADXL345, connected to the I2c-bus, and when connected well, you will find it in the I2c-scanner. This is the Bascom-AVR code for the I2c-scanner. When the ADXL345 and the HMC5843 are fixed on the board you should see this in Hyperterminal.
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Ergonomics and Manpower the Engine of Growth
A Worker in One Firm is a Customer for another Firm. Healthy and Safe Workers implies a strengthening Consumer base.Just imagine what wonders it can do for the economy, when you broaden your view, think togetherness, as a Whole; not in isolated competitive groups, not in parts.
Ergonomics reduces Worker Stress. Helps in keeping good Mental and Physical Health. Safety is very important. His Limbs, Eyes and Ears are assets that a firm hires. On this page you can start learning these aspects. A good Manager knows that Manpower is the Foremost Asset of any Company.
- Product should not give even the lightest shock, Even metal parts on user side to be laminated.
- High energy circuits never enters analog and digital circuit areas without Opto or other Isolation.
- Gadgets, Furniture, Tools and Storage Units should not cause injury. Rounded Edges, Non Toxic.
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Product DesignWhen you wish to Begin to learn Electronics, first a short study of Physics is essential, secondly some Electronics theory. Then build simple and small gadgets to learn Practical Electronics while working with Educational Hobby Circuits. Lastly to make your own product designs, a fundamental knowledge of Analog and Digital Electronics is the foundation for your next steps into Engineering a Design.
Applications and ComponentsThe basic building blocks for most circuits are Chips or ICs. You can acquire considerable knowledge by studying Application notes of National Semiconductor and Texas Instruments to start with. When you want to use a Microprocessor or Build Your Own Microcontroller Projects, you can study the documents at Atmel and Microchip to begin. The Specifications and Behavior of Passive Components like inductors, capacitors and Resistors; Discrete Semiconductors; Power Devices. and RF Components have to be understood well, in order to design sturdy Industrial Grade Designs eg. ST.
Here is a complete project which will help in learning to apply the CA3140 in a small instrument that could be used in your test bench along with the oscilloscope. It is necessary to study the datasheet for understanding the device and this application with full details.
"A function generator having a wide tuning range is shown in Figure 10. The 1,000,000/1 adjustment range is accomplished by a single variable potentiometer or by an auxiliary sweeping signal. The CA3140 functions as a non-inverting readout amplifier of the triangular signal developed across the integrating capacitor network connected to the output of the CA3080A current source."
Meter Driver and Buffer Amplifier
Figure 11 shows the CA3140 connected as a meter driver and buffer amplifier. Low driving impedance is required of the CA3080A current source to assure smooth operation of the Frequency Adjustment Control. This low-driving impedance requirement is easily met by using a CA3140 connected as a voltage follower. Moreover, a meter may be placed across the input to the CA3080A to give a logarithmic analog indication of the function generator’s frequency.
Sine Wave Shaper
The circuit shown in Figure 12 uses a CA3140 as a voltage follower in combination with diodes from the CA3019 Array to convert the triangular signal from the function generator to a sine-wave output signal having typically less than 2% THD.
Triangle and Square Wave Generation
Buffered triangular output signals are then applied to a second CA3080 functioning as a high speed hysteresis switch. Output from the switch is returned directly back to the input of the CA3080A current source, thereby, completing the positive feedback loop
The triangular output level is determined by the four 1N914 level limiting diodes of the second CA3080 and the resistor divider network connected to Terminal No. 2 (input) of the CA3080. These diodes establish the input trip level to this switching stage and, therefore, indirectly determine the amplitude of the output triangle.
Figure 13 shows a sweeping generator. Three CA3140s are used in this circuit. One CA3140 is used as an integrator, a second device is used as a hysteresis switch that determines the starting and stopping points of the sweep. A third CA3140 is used as a logarithmic shaping network for the log function. Rates and slopes, as well as sawtooth, triangle, and logarithmic sweeps are generated by this circuit.
Wideband Output Amplifier
Figure 14 shows a high slew rate, wideband amplifier suitable for use as a 50Ω transmission line driver. This circuit, when used in conjunction with the function generator
and sine wave shaper circuits shown in Figures 10 and 12 provides 18VP-P output open circuited, or 9VP-P output when terminated in 50Ω. The slew rate required of this
amplifier is 28V/μs (18VP-P x π x 0.5MHz).
Power Supply for Project
Use a good step-down transformer to isolate the mains supply and reduce the AC voltage. Rectify with a diode bridge to get DC, filter the DC with large electrolytic capacitors. Then implement this Dual Power Supply circuit along with LM7815 and LM7915 - Dual Polarity Power Supply
Amps-n-Volts eMag Near 2001 i started sharing my learning and experience in Electronics Engineering on Blogs and Newsletters. One of the Successful eMag and electronic email magazine ran for five years. I lost interest later in the email mag, and this magazine just morphed into a dozen or more Tech Blogs that run today.
From the feedback i got, i am happy to sense that it has helped engineers and enthusiasts worldwide in Electronic Product Design. These blogs contain most of the Magazine - Schematics of delabs - Soldermans Basics - Circuits Faq
My knowledge is limited to my experience, observation, perception, learning and beliefs, but i have to express my views freely. These posts are mirrored in design devices.
Some Technical Points
- Before you open a PC remove power, telephone modem and LAN cables else finger and screwdriver in wrong place can zap chips.
- The products that survive the infant mortality time of say first six months will last quite long.
- NTSC is like 320 x 240 pixels, which is TV, which is lower than your computer's 800 x 600.
- When a microwave oven is turned on, a big spike is caused in the power line due to heavy inrush current on start up, Even pumps and motors cause such short time surges. This causes tripping of electrical protection circuits.
- When a tree branch falls on the high voltage overhead electrical lines, they spark violently and supply trips.
- Big or tall trucks go in small roads they may snap all low level cable or telephone wires on their way.
- Do you need to turn on many equipments-machines all at once? do it one after an other sequentially or use a timer for delays. This is because at peak power demand time, turning on all can cause your fuse to blow or worse.
- A battery that can be charged is best charged in CC constant current and CV constant voltage modes, that means both current and voltage have to be limited. When a battery is deep discharged many times it will age fast, and an empty battery will take huge currents so limit current. overcharging a battery will killit. After a voltage level is reached it should only trickle charge in mA and a battery has to be cut off on overload or before deep discharge
- The Lead acid battery breathes a lot, so keep them in a well ventilated open space but rain proof. Use sealed maintenance free battery when possible, these are safer.
- Teflon tape can be used to make leak proof pneumatic or hydraulic connections if junctions are leaking.
- The current thru a 3mm or 5mm LED (light emitting diode) should not exceed 20mA, 15mA is quite good.
- In a circuit swap all PNP and NPN , reverse all diodes and el-caps, reverse the supplies and input polarities, most of the circuit may still work like they did before.
- A sharp bend in a PCB track is a huge inductance (say 1nH ) when it comes to RF. it may radiate or reflect, it may even act like an antenna and pick up RF from the SMPS, Motor or Cellphones nearby.
- Persistence of vison around 16 frames a second (60mS) hence very fast events not seen .
Some of these points may be repeated and some not relevant in the present technical engineering scenario. As issues may have been set right, years back.
- Design Notes - Analog and Opamps - 01
- Design Notes - Power Electronics - 02
- Design Notes - Power Electronics - 03
- Design Notes - Schematic and PCB - 04
- Design Notes - Components Selection - 05
- Design Notes - Analog Basics - 06
- Design Notes - Product Development - 07
Analog Product Design Article Count: 2
Most of my early life as a R&D Engineer, i have been in Analog. Here are design aspects of circuits using Op-amps and Comparators. Discrete Semiconductor Circuit design like using Transistors and Diodes. RLC parts. The related blog is my delabs Schematics.
Electronic Design Article Count: 4
Things related to Electronic Design in all its aspects. That includes the prototyping, mechanical, electrical and PCB. Product Safety, EMI-RFI, Reliability and Robustness. The related blog is here Design Gopher
Embedded Systems Article Count: 7
This Section is related to Microcontrollers and Related Resources. Microcontroller, SOC, FPGA, ASIC. From 80C31 to the Latest ARM chips will be the scope of this section. The related blog is here Hyper Embedded
delabs Technologies Article Count: 1
Product Design - Industrial Automation and Instrumentation. delabs Technologies uses the brand names delabs and dapj in its Web Services and Resource Sites. These together form an Electronics Informatics and Product Design Technologies Web Consultatory. Updates are Here delabs SmartView.
Power Electronics Article Count: 2
The design of Power Supplies, DC to DC and AC to DC Convertors, SMPS, High Voltage and High Current equipment. Mosfets, Thyristor, Schottky Diodes, Ferrite Magnetics and Chokes are the various components used. Power Electronics qt delabs.
- MC7800 MC7900 1 Amp Voltage Regulators
- Function Generator using the CA3140
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- Switches in Electronics
- Power Quality and Clean Energy
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- USB Serial Interface
- PIC Microcontroller
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