CS289 Ver la hoja de datos (PDF) - Cherry semiconductor

Número de pieza

componentes Descripción

Fabricante

CS289

20mA Air-Core Tachometer Drive Circuit

Cherry semiconductor 

Tachometer Application

RPM x # OF CYL.= Frequency

60

2

VF/VOUT = 2.1 + Frequency x CT x RT (VREG -0 .7)

The above equations were used in calculating the follow-

ing values, where VF/VOUT = 7.1V at =270¡ and CT = 0.01 F.

4 cylinder: Freq = 200Hz, RT = 320k½

6 cylinder: Freq = 300Hz, RT = 220k½

8 cylinder: Freq = 400Hz, RT = 150k½

Typical values shown above apply to a nominal value of

VREG of 8.5 volts. It must be realized that trimming of RT

will be necessary to compensate for variations in regula-

tor voltage from one unit to another.

An alternative to this adjustment is to replace R2 with a

potentiometer, as shown in Figure 2.

Partial schematic shown in Figure 3 represents one met-

hod for use with DC applications instead of frequency.

TRIM

10kW

IOUT/EQ

RT

CP

CT

1kW

Figure 2: Alternate Trimming Method

RT

CP

0.7V

IIN

Figure 3: DC Application

2.1V

5

Share Link: