Institute for Astronomy

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Howard Wells
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1 . 5 Unless otherwise stated: esistors are / Watt, % tolerance apacitors are 50V, 0% tolerance ISION LOK ESIPTION TE INOP. Y. Parts list is a nominal list. Substitute equal, tighter tolerance, higher power, or higher voltage parts as desired. ables going to TS Servo ox Simulated Tach oard (unbolted & lifted for viewing) mplifier oard TSLT University of Hawaii Institute for stronomy TS Lab Tachometer mplifier & ables of 5 ENGINEE LST EIT E. Warmbier //00 5::7 PM FILE: Y:\public_html\tcs\esign\Lab_System\electronics_docs\TS Lab Tachometer mplifier.vsd 5 WG # TITLE

2 5 (West) P (West) P (East) P (East) P 00k 00k 5 0% 7 0 0% VS VS VS VS 0k U P 7 0k U P 00, 5% 9 00, 5% 9 P9 (W IVE TH) P0 (W IVE TH) P (E IVE TH) P (E IVE TH) VS 0 VS 9 V V.5W W V V.5W 00 5W P5 (V) P (V TN) P (TN) P (V TN) P (V) (North) P (North) P5 00k 5 0% 5 VS VS 0k U P 0 00, 5% P (N IVE TH) P (N IVE TH) (South) P (South) P7 5 00k 9 0 0% 7 VS VS 7 0k U P 00, 5% 9 P5 (S IVE TH ) P (S IVE TH) NOTE: djust gain of each stage to.0, using the pot. WG # TSLT 5 of 5

3 5 P West West V0 GN East East V GN From Tachometer Simulator oard North 5 V mplifier oard North South 7 GN V South GN W IVE TH 9 W IVE TH W IVE TH E IVE TH E IVE TH 0 W IVE TH E IVE TH E IVE TH To Servo ox N IVE TH N IVE TH P05 S IVE TH 5 N IVE TH S IVE TH N IVE TH S IVE TH To Servo ox S IVE TH P0 WG # TSLT 5 of 5

4 5 PTS LIST FIN # QTY Part # escription ef es omment esistor, Ω, /W, %,,,9,,,,9 esistor, 0kΩ, /W, %,7,,7 esistor, Ω, /W, %,,, esistor, 00 Ω, 5W, %,9,9, 5 esistor, Ω, /W, 0% 5,0,5,0 P Power amplifier U 7 apacitor, tantalum,.7 uf, 50V 0 apacitor, ceramic,, 50V 0 9 esistor, Ω, /W, 5% 0.5KE Zener iode, V V, V esistor, 00 kω, /W, %,,,5 Potentiometer, Ω,7,,9 onnector, Molex, pin P onnector, Molex, 5 pin P 5 MSF09SW onnector, 9 socket P05 MSF09SZ onnector, 9 socket P0 7 Fan, PW00 Power Supply, V 9 rimp on fork terminals WG # TSLT 5 of 5

5 5 UENT LIMITING Since this is driving a high impedance load (/ input), let s set the current limit to something low like 0m. From previous calculations, our gain is and maximum / output is 0V. Therefore, the maximum output voltage is 0V. Using the equation from the P datasheet for the current limit and entering our parameters: L L L L = 0.5 / I = 0.5 / 0.00 =.5Ω Ω L POWE SUPPLY INPUT POTETION The P amplifiers can have /50 supplies max. / V leaves only V of margin. The maximum voltage that needs to be output is about 7V (see below right). Therefore a simple resistor/zener combination will work to drop and clamp the voltage. 00 Ω, 5W resistors were found in the lab. With about 00m of quiescent current draw, this equals 0V (00m x 00Ω) of drop on each supply, or /V approximately. This leaves V 7V = V of margin that is sufficient for opamp headroom, small variations in quiescent current over time, etc. Since the opamps power high impedance loads, no additional current will be drawn from the supplies, so having a large resistance in series will not lead to large supply voltage fluctuations. Placing a V zener after the resistor will clamp the voltage to a safe level if the voltage supplied is too high. Voltage (V) (Intercept set to Zero) TS Tachometer Voltage vs. Speed y = 0.005x = y = 0.007x = y = 0.005x = East West verage Linear (West) Linear (East) Linear (verage) Speed (as/s) MXIMUM OUTPUT VOLTGE The slope of the tachometer is about.7mv/(arcsec/s). urrent TS slew speeds are in excess of arcsec/s and the TS maximum velocity could be raised to a similar value. Therefore, the lab setup should be capable of simulating at least 000 arcsec/s for the overspeed. 000 arcsec/s *.7mV/(arcsec/s) =.9 V P mplifier Pinout MPLIFIE GIN The lab system can currently output up to 0V maximum. Therefore the gain of the amplifier must be: Min_Gain=.9/0 =.9 For margin, round the gain up to. The amplifier is a noninverting configuration with a gain of: Gain=(f/s) Entering in the desired gain of will result in a resistor ratio of: =(f/s) =f/s WG # TSLT 5 5 of 5

HA Axis Parameter TCS1 Simulink Comment Tracking Velocity Average

HA Axis Parameter TCS1 Simulink Comment Tracking Velocity Average ackground This document compares the TS1 actual operation with the SIMULINK model as of ecember 2007. Tracking, offset, and slew modes are compared using velocity magnitudes, pulse widths, acceleration,