3BDH000014R1輸入特性模件,3BDH000014R1參數(shù)說明
數(shù)模轉(zhuǎn)換器
D/A轉(zhuǎn)換器接收來自微處理器。它將數(shù)據(jù)從數(shù)字字轉(zhuǎn)換為等效模擬信號(hào)。D/A轉(zhuǎn)換器將模擬日志位置需求輸出到位置誤差電路。位置誤差位置誤差電路將位置需求與位置反饋進(jìn)行比較。該電路的輸出為差值在位置反饋和位置需求信號(hào)之間。
該信號(hào)傳輸至伺服放大器。當(dāng)位置需求和位置反饋為相同的當(dāng)放大器輸出為零時(shí)，表明執(zhí)行器處于正確位置，伺服放大器保持伺服閥就位，執(zhí)行器保持其位置。
3BDH000014R1輸入特性模件伺服放大器伺服放大器提供驅(qū)動(dòng)伺服閥的電源。
有兩個(gè)伺服驅(qū)動(dòng)輸出并聯(lián)，在控制輸出中提供冗余。每個(gè)輸出連接到單獨(dú)的線圈。伺服閥操作只需要一個(gè)工作線圈。一個(gè)輸出可以對地短路或開路，而不影響其他伺服驅(qū)動(dòng)輸出。如果一個(gè)伺服驅(qū)動(dòng)輸出失敗，則其他輸出能夠驅(qū)動(dòng)伺服閥。
抖動(dòng)振蕩器抖動(dòng)振蕩器將小幅度的振蕩引入伺服閥，以幫助其克服摩擦的影響。
在閥門位置很少變化的系統(tǒng)中，抖動(dòng)振蕩器防止閥門凍結(jié)在一個(gè)位置。
位置反饋塊由三部分組成（參見圖2-4）：
?解調(diào)器。
?A/D轉(zhuǎn)換器。
?LVDT振蕩器。
解調(diào)器LVDT二次側(cè)通過產(chǎn)生與變壓器鐵心位置成比例的差分電壓來響應(yīng)液壓執(zhí)行器的移動(dòng)，該變壓器鐵心隨著電壓的變化而移動(dòng)執(zhí)行器移動(dòng)。由于LVDT次級(jí)是線性的，因此校準(zhǔn)變壓器二次側(cè)的感應(yīng)電壓具有全范圍的節(jié)流閥。有一個(gè)最大值
DIGITAL-TO-ANALOG CONVERTER
The D/A converter receives the position demand from the
microprocessor. It converts the data from a digital word to an
equivalent analog signal. The D/A converter outputs the ana
log position demand to the position error circuit.
POSITION ERROR
The position error circuit compares position demand with posi
tion feedback. The output of this circuit is the difference
between the position feedback and the position demand signal.
This signal goes to the servo amplifier. The position error out
put is zero when position demand and position feedback are
equal. When the amplifier output is zero, indicating that the
actuator is in the correct position, the servo amplifier holds the
servo valve in place and the actuator holds its position.
SERVO AMPLIFIER
The servo amplifier provides the power to drive the servo valve.
There are two servo drive outputs in parallel providing redun
dancy in the control output. Each output connects to separate
coils. Servo valve operation requires only one functioning coil.
One output can short to ground or open without affecting the
other servo drive output. If one servo drive output fails, the
other output is able to drive the servo valve.
DITHER OSCILLATOR
The dither oscillator introduces an oscillation of small magni
tude to the servo valve to help it overcome the effect of friction.
In systems where valve position rarely changes, the dither
oscillator prevents the valve from freezing in one position.
Position Feedback
There are three parts to the position feedback block (see
Figure :
?
Demodulator.
?
A/D converter.
?
LVDT oscillator.
DEMODULATOR
The LVDT secondaries respond to the movement of the hydrau
lic actuator by generating a differential voltage that is propor
tional to the position of a transformer core that moves as the
actuator moves. Since the LVDT secondary is linear, the
induced voltage on the transformer secondary is calibrated
with the full range of the throttle valve. There is a maximum
