Featured Post

High CMRR Instrumentation Amplifier (Schematic and Layout) design for biomedical applications

on
Instrumentation amplifiers are intended to be used whenever acquisition of a useful signal is difficult. IA’s must have extremely high input impedances because source impedances may be high and/or unbalanced. bias and offset currents are low and relatively stable so that the source impedance need not be constant. Balanced differential inputs are provided so that the signal source may be referenced to any reasonable level independent of the IA output load reference. Common mode rejection, a measure of input balance, is very high so that noise pickup and ground drops, characteristic of remote sensor applications, are minimized.Care is taken to provide high, well characterized stability of critical parameters under varying conditions, such as changing temperatures and supply voltages. Finally, all components that are critical to the performance of the IA are internal to the device. The precision of an IA is provided at the expense of flexibility. By committing to the one specific task of
2

2.5A-1.25 To 25V Regulated Power Supply Circuit Diagram

on
This power supply uses an LM317J adjustable regulator and an MJ2955 pass transistor. Ql and U2 as well as Ul should be heats inked. A suitable heat-sink would typically be 4` 4` 1` fins, extruded type, because up to 65 W dissipation can occur. R8 and R9 should be 1% types or selected from 5% film types with an accurate ohmmeter. Capacitors are disc ceramic except for those with polarity marked, which are electrolytic. D1, D2—1-A, 100-PIV rectifier diode. DS1—Red LED. F1 —1,5-A, 3AG fuse in chassis-mount holder. J1, J2—Standard five-way binding post, one red, one black. M1—Milli-ammeter, 0-1 mA dc. Q1—NPN power transistor MJ2955 (Radio Shack) or equiv device with a + 70-V, 10-A, 150-W rating in a -204 case. R1, R2, R7—5-W wire-wound resistor. See Notes 3 and 4 for source, or, use 17 inches of no. 28 enam wire, single-layer wound, on a 10-KOhmhm, 1-W carbon-composition resistor for R1 and R7. For R2, use 36 inches of no. 30 enam wire on a 10-KOhmhm, 1-W carbon composition resistor (scramble wound). R-4—Panel-mount, 5-kfi, 2-W or 5-W potentiometer, carbon or wire wound (See Note 8). R8, R9—See text. 51—SPST toggle switch. 52—DPDT toggle or rotary wafer switch. T1—25.2-V, 2.75-A power transformer (see text). U1—6-A, 200 PIV bridge rectifier with heat sink. See text. U2—LM317T +1.25- to 30-V, 1.5-A 7-220 regulator. Use an LM317HVK (T0-204 case) for dc output voltage greater than 40. See text.

2.5A-1.25 To 25V Regulated Power Supply Circuit Diagram

2.5A-1.25 To 25V Regulated Power Supply Circuit Diagram

Comments

Post a Comment