NTE1885 查看數據表（PDF） - NTE Electronics
零件编号
产品描述 (功能)
比赛名单
NTE1885 Datasheet PDF : 4 Pages
| |||
When the voltage drop of the emitter resistor R16 (internal) has increased up to the external stan-
dard voltage and the set voltage (the voltage of Pin9), the comparator output becomes Low and
TR7 turns OFF with TR1 OFF. The point at which the comparator output changes from Low to
High is called the Upper Trip Point and is expressed as VUTP.
since
VUTP =
=
R16 =
V9
RO2 + R16
VCC2 x
RO1 + RO2 + R16
0.3Ω ±5%
and R16 << RO1, RO2 is negligible
therefore VUTP =
where
RO2
VCC2 x
RO1 + RO2
RO1 and RO2 are the motor series winding resistors
When the comparator output becomes Low with TR1 OFF, the winding current decreases as fol-
lows:
VCC – V(sat)
i=
x ε–t/τ
R
When the voltage at Pin8 reaches a certain value, the comparator output becomes High and TR1
turns ON with an increase in the winding current. These steps are repeated. The point at which
the comparator output is changed from Low to High is referred to as the Lower Trip Point, ex-
pressed as VLTP. At VLTP, energy stored in the winding L1 and is discharged through TR2, R16,
R17, D4 and L2, and feedbacked to L1. Therefore, half of IOH flows into R17 and the voltage at
Pin8 becomes 1/2 VUTP.
VLTP = 1/2 x VUTP
The change of the motor winding current is as follows:
VUTP
IOH =
R16
VLTP
IOL =
R16
The flyback voltage generated by the turn OFF of TR2 phase drive, is returned to the power supply
through TR2, R16, R17, D4, L2, and D1, providing low power consumption.
Typical Application Circuit
+VCC1 (36V)
ZD (43V.3W)
A
A
B
B
Power Down Input
Pause Action Input
+5V Reg Voltage
22k RO1
31
5
0.1µf
2
10µf
6
4
13
7
14
16
17
12
18
15
8
9
4 Phase Stepping Motor
10
1k RO2
Share Link: 