Basic operating principles of Sampling Gates

The basic operating principles of a sampling gates are illustrated in figures (a) and (b).a) Series Switch.b) Shunt Switch. In figure (a) the switch is normally open, but is in closed position when the signal is transmitted.In figure (b) the switch is normally closed, but is in open position when the signal is transmitted.These switches are normally electronic-devices diodes or transistors.When the device is conducting , it acts as a closed switch and when the device is not conducting, it acts as an open switch.Ideally a closed switch should have zero resistance and an open switch should have infinite resistance.But semiconductor devices do not have infinite back resistance and their forward resistances may lie in the range of several ohms.When such devices are used as switches, there is no specific advantages of either the series or the shunt switch position.The choice of the circuit depends upon the particular application....
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Frequency compensation

For low closed loop gain and high band width frequency compensation is used in op-amp There are two types of frequency compensation techniques they are:Internal frequency compensation technique.External frequency compensation technique.Internal Frequency Compensation Technique :It makes use of internal components for compensation.Usually used in instrumentation amplifiers. Also called as internally compensated op-amp.IC741 contains capacitance C_1 = 30pf which internally shunts off signal current and thus reduces available out put signal at higher frequency.The internal capacitance C1= 30pf the compensating  element which causes open loop-gain to roll off at -20dB/decade rate and gives a stable circuit.Bandwidth product of op-amp is 1mHz and if IC741 is wired for a closed loop gain of 104/80dB then its bandwidth is 100hz for a gain of 102 bandwidth.  The bandwidth increase to 10KHz with gain one making bandwidth 1Mhz. External Frequency Compensation Technique :These circuit fuse external frequency components to give low closed loop gain. The two common methods are:Dominant pole compensation.Pole zero compensation.  ...
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Managerial Skills

It is of three types. They are:Conceptual Skills Human Skills Technical Skills Conceptual Skills:It is referred to as creative ability. It should be passed by top level management as the top level management involve in decision making of an industry. Conceptual skills includes knowledge about the product to be produced. It's marketing and financing and to look after weather the production is able to meet the required demand.Human Skills:It is primarily concerned with working by people. For the process of production, leadership, motivation, super vision, co-ordinations, control of workers is required. This skills are passed by all levels of management. As at each and every level it involve in a group.Technical Skills: It refers to the proficiency in handling methods and process techniques of a particular kind of activity. This is very much needed in lower levels of the management.  Brief description of management levels ...
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Levels of Management:

Management levels are classified into 5 types: Top Level Management.  Upper Middle Level management. Middle Level Management. Lower Level Management. Operating force management. Top Level Management: It include board of directors, managing directors, CEO, owner of the business, share holders, financiers, investors etc. Functions:  Setting basic goals and objectives. Expanding of contracting activities. Establishing policies. Monitoring performance and designing/ redesigning organization system. Financial responsibilities. Upper Middle Level Management: It includes sales executive, production executive, finance executive, Accounts, R&D executive etc. Functions:  Establishment of the organization. Selection of the staff for lower levels of management. Installing different departments. Designing operating policies. Assigning duties to their subordinates. Middle Level Management: It includes superintendent, branch managers, general manager forcement. Functions:  To coparated to run organization smoothly. To conduct training for employ development. Lower Level Management: It includes foremen, supervisor, superintendent and interceptor. Functions:  Direct supervision of workers and their work.  Developing and improving working methods. Inspection function to give finishing touch to the plans and policies of the top level management. Operating Force: It include workers rank and files workmen,...
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Stability of An Op-Amp:

Consider an op-amp with negative feedback which uses a feedback resistor network which may be used as an inverting amplifier for V­­2 = 0 and non-inverting amplifier V1 = 0 The closed loop transfer function is given by ACL = A/1+Aβ Where; A : open loop voltage gain                B : Feedback ratio If (1+Aβ) = 0 the circuit will become unstable and gives sustained oscillations. Re-writing 1+Aβ = 0 as 1-(-Aβ) = 0 leads to –Aβ = 1 Aβ is a complex quality Therefore, │Aβ│ = 1 and phase condition Lle- Aβ =0 or (multiple of 2π)                                                                           Lle- Aβ =1 or (multiple of π)   Since, resistor is the present in feedback network it does't provide any phase shift. When op-amp is used in inverting mode it provides phase shift  Of 180o and at low frequencies. However at high frequencies due to each corner frequency an additional phase shift of maximum -90o can take place in open loop gain phase. So, for two corner frequencies maximum phase shift is added Hence at...
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AC Characteristics of an op-amp

For small signal sinusoidal applications the AC characteristics of op-amp are discussed as follows:Frequency responseStability of an op-ampFrequency CompensationSlew RateFrequency Response :An ideal op-amp should have infinite band width. If open loop gain is 90 dB with DC signal then it should remain the same for audio and radio frequencies also but practically the op-amp gain deceases / roll's off at higher frequencies hence a capacitor component is placed in a circuit of op-amp      For an op-amp with one corner frequency all the capacitor effects can be represented by single capacitor.     The following is a high frequency model of an op-amp:  The open loop voltage gain is obtained as:        V0  = [-jXc/(R0 - jXc)] AOLVd(or) A = V0/Vd = AOL/ 1+j2πfR0­CA = AOL/ 1+j(f/f1)f1 = 2πR0­CThe magnitude and phase angle of open loop gain is│A│ = AOL/ 1+(f/f1)2   (or) Ф = tan-1 (f/f1)...
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Functions Of Management

According to Luther Gullick management is "POSDCORB"   P - Planning O - Organizing S - Staffing  D - Directing  Co - Coordinating R - Reporting B - Budgeting According to Henry Fayol the management is of five types : Planning Organising  Staffing Directing Controlling Planning: It is referred to deciding now what is to be done in the future. The gap between the present and future. The corporate goals set the direction for planning function Elements of Planning:  Monagers develop the following so that they can be used up to carry out their plans forecast, objectives, policies, strategies, programs, procedures, schedulers, budgets etc. Organizing:  It is refer to the process of grouping the related activities and assigning them to a manager with authority to supervise it. Organizing make organizational environment more conductive for group effectiveness. The function of organising to create higher managerial position that the employees would to reach the problem. Staffing:   How many positions are there in the organization and at what level of position? Once this...
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Thermal Drift

Bias Current, Offset current, offset voltage change with temperature then a circuit is maintained at 250 room temperature. It does not remain so, and temperature raises to 350 which is called as drift. Usually current drift is expressed in nA/0c where offset voltage drift is expressed in mv/0c.Effect of thermal drift is minimized by cooling or placing PCV away from heat           ...
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Input offset voltage

Inspite of all the compensation techniques the output voltage is still not zero with zero input voltage.  Hence a small voltage is applied at the input terminals to make output voltage zero which is called as input offset voltage. The following are the non-inverting and inverting amplifiers respectively: Where  V1 =0 gives Voltage V2 is given by    V2 = V0 [R1/(R1+ Rf)] Or  V0 = V2 [ (R1+ Rf)/ R1] Since, Vios = │V1 – V2│and Vi = 0 Vios = │0 – V2│ =  V2 V0 = [1+(Rf/R1)] Vios...
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Input Offset Current

It is the difference between the current flowing from inverting and non-inverting currents of an op-amp.              Ios = IB+ - IB-   With bias current compensation the offset current will produce an output voltage when the input voltage is zero We have,           V1 =IB+ Rcomp             And   I1 = V1/R1 KCL at node ‘a’ gives            I2 = (IB- - I1)               = IB- [IB+ (Rcomp/R1)] Also,                 V0 = I2 Rf - V1           V0 = I2 Rf - IB+ Rcomp              = [IB- - IB+Rcomp]Rf - IB+Rcomp We know, Rcomp = R1Rf / R1+Rf Substituting Rcomp, we have,         V0 = Rf [IB- - IB+] The effect of offset current can be minimized by keeping feedback resistance value be small  ...
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