Proper construction and testing procedures.

1. Probably the largest percentage of problems encountered by the unitiated involved either improper
construction or inappropriate testing. First, let us consider the prototype or breadboard — the stage at which the
basic circuit design is tested and evaluated. There are five methods available for constructing the prototype: the
custom pc (printed circuit) board; the vectorboard with sockets and point-to-point wiring; special sockets,
wirewrap sockets, and lastly, standart pc boards, with a foil pattern to accommodate only one ICs (or their
sockets where interconnections are wired in to suit a particular situation. Each of these methods offers certain
advantages, while also presenting limitations and its own unique problems.

No single method is best for all cases.

2. The wirewrap technique is applicable where few discrete components are used and where the exact
circuit configuration has not been finalized in the design stage. The wirewrap technique is not advised where
signals of I MHz or higher are used. This technique although offering flexibility, makes the prototype somewhat
hard to troubleshoot in terms of finding a wiring mistake or in tracing signals. This techique is especially well
suited for digital circuits of great complexity.

3. Standard pc boards offer a good compromise between the custom pc board and point-to-point wired
vectorboard. They are available in two types: one to accommodate DIPs (dual in-line package ICs), one to
accommodate the round TO-5 type packages. The advantage of this scheme over the wirewrap is that it does not
require special tools, and like the wirewrap technique, this scheme is probably better suited to digital applications.

4. Special sockets which can accommodate up to about 100 1C pins (not ICs) are a good choice for simple
digital as well as analog prototypes. They provide interconnection points for wires or discrete components next to
the 10 pins. This scheme offers the easiest and most convenient means for changing the circuit since no
soldering is involved. However due to the high capacitance between sockets, this method is not advised for
signal frequencies much above 500 kHz.

5. The vectorboard approach offers the widest latitude in parts location, since this is entirely determined at
the user's discretion. It is probably the most tedious and slowest method — each socket and external component
must be individually mounted and interconnected.

PROPER POWER SUPPLY

6. This is the last consideration because, it is recommended to use a good commercial regulated power
supply for the initial prototype evaluation. In this way the power supply is eliminated from the possible list of
problems that may originally arise. In addition, there is no need to guess or estimate the power supply
characteristics necessary for the finalized project.

Words to be remembered:

to evaluate — оценивать, давать оценку, определять качество

to estimate — оценивать, давать оценку, выносить суждение

to involve — включать в себя, заключать, влечь за собой, вызывать

to suit — удовлетворять требованиям, быть удобным, устраивать

convenient, adj. — удобный

latitude — широта

tedious — скучный, утомительный

tc determine — определять

to mount — I) взбираться, восходить

2)устанавливать, монтировать

6. Переведите следующие слова и словосочетания:

proper circuit design; limitations of ICs; offers certain advantageous; exact circuit configuration; tracing signals; the scheme is better suited to; convenient means, widest latitude.

7. Ответьте на вопросы к тексту:

1.What are the methods available for constructing the prototype?

2. When is wirewrap technique applicable?

3. What is the advantage of standard ps board over wire wrap sockets?

4. What is the nost tedious and slowest method?

5. What is the advantage of special socket technology?

8. Переведите предложения, обращая внимание на подчеркнутые слова:

1.Large valued reristors are either avoided through circuit design, or pinched resistors are used.

2. Neither this method nor previous one could be used in the 1C design.

3. Either vacuum evaporation or cathode sputtering of the desized material can be used in the fabrication of
thin film hybrid circuit elements.

4. Neither size nor weight can be reduced by applying thus method.

5. None of these objectives can be appreciably compromized in the achievement of a practical operating
microsystem.

6. NO single method is best for all cases.

7. No simple way has been found to eliminate this limitation.

8. It should be pointed out that the figure by no means includes all possible 1C configurations.

9. In ICs of a high scale of integration it is possible to design a connection layout so as to exclude
crossovers unless a multilayer is used.

10. Conversion of the surface layer of a solid to a solution is thing else than elimination of this layer.

9. Напишите аннотацию к тексту.

10. Докажите правильность или ошибочность суждений. Дайте расширенный ответ.

1.There are 5 methods available for constructing the prototype.

2. Bach of these 5 methods can be used in all cases.

3. Either wirewrap or standard p.c. boards are suited to digital application.

4. The wirewrap technique is advised where signals of 1 MHz or higher are used.

11. Прочитайте текст С.