JPS6214215A - Lamp control system - Google Patents

Abstract

PURPOSE:To make it possible to make soft start time of lamp voltage constant regardless of fluctuation of power source voltage by finding effective value of specified phase angle of power source voltage and adjusting phase angle of power source supplied to a lamp. CONSTITUTION:Control of lighting voltage of a lamp is made by a system that widen phase angle successively, and thereby, soft start time (time from starting of lighting of a lamp to arrival at a set voltage level) of lamp voltage is controlled. Effective value of voltage (black part) of phase angle in power source voltage at the time of putting out of light, and phase angle alphaS is adjusted to make the effective value and set voltage (target voltage) equal. Difference between the phase angle alphaS and phase angle alpha1 at which voltage at the time ofstarting lighting of the lamp becomes a specified value is made soft start time. When it becomes a lamp ligthing mode, phase angle is widened by phase angle DELTAalpha from voltage of phase angle alpha1 at every half wave, and changed to normal phase control when arrived at set voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a lamp control method in which the lighting voltage of a lamp is controlled by a microcomputer, and particularly to a soft start control method thereof.

(Prior art) The soft start time of the halogen lamp used as the original exposure lamp of a copying machine is approximately 200m5EC (models with a copy speed of 40 sheets/min or less). However, in the conventional soft start method, the power supply voltage or set voltage The method used was to gradually widen the phase angle by a constant interval even if the phase angle changed.

Therefore, when the power supply voltage is lowered or when the set voltage is increased, the phase angle becomes wider and the time required to reach the set voltage level becomes longer. As a result, there was a drawback that the desired amount of light could not be obtained during that time and the leading edge of the copy would become black.

(Purpose) The present invention solves these drawbacks of the conventional example, and eliminates the soft start time of the lamp voltage (the time from the start of lamp lighting until reaching the set voltage level), regardless of fluctuations in the power supply voltage or the value of the set voltage. ) is always kept constant.

(Structure) First, an outline of the soft start control system according to the present invention will be shown based on FIG.

(1) in Figure 1 is the case where the phase angle is widened every half wave,
(n) is the case where the phase angle is widened for each wave, and both are 5
This is an example at 0H2.

To explain (1), first, when the lamp is turned off, the effective value of the voltage at the phase angle α3 (blacked out part) of the power supply voltage is determined, and the effective value is determined so that the set voltage (target voltage) is equal to the effective value. Adjust the phase angle α. And the phase angle α
, and the phase angle α (5/6 α at 50 Hz and 60 Hz) at which the voltage at the start of lamp lighting is about 10 Vrm3 is the soft start time, more precisely the time using half a wave from the soft start time. That is, the value Δα divided by 19 half waves (50H2) or 23 half waves is set as the phase angle increment value at the time of soft start (formula 0).

Next, when the lamp lighting mode is entered, the voltage at phase angle α1 (or 5/6α1) is half i21! A☆phase angle Δα
When the set voltage number is reached, the phase angle is changed by the difference between the set voltage and the detected voltage (row line part).

In the case of (■), it is the same as day →, and the lamp is turned off. In particular, L2 (t'l) is equal to the set voltage. Find the phase angle α, and calculate the difference between α and α1 (or 5/6α1) with the soft star 1. 1 from time
Time after the wave subsided, 9 waves (50112) or 1
The angle Δα divided by one wave (60 Hz) is taken as the phase angle increment value at the time of soft start. ((2γ formula).

Next, when the lamp lighting mode is entered, the phase angle is increased by Δα for each wave from the voltage at the phase angle α1 (or 5/6αI), and when the set voltage is reached, normal phase control is started.

As described above, even if the power supply voltage or set voltage changes, the phase angle is widened at intervals of the phase angle α corresponding to the change, so a constant soft start time can always be obtained.

Next, a concrete example will be explained.

FIG. 2 shows a circuit configuration of one embodiment of the present invention.

In Figure 2, No. 1 is a commercial power supply 1t[, 2 is a transformer that isolates and steps down the commercial power supply voltage 1, 3 is an aftereffect rectifier 11, and the peak IW is 5V (when the commercial power supply voltage 1 is 115Vrms)
4-digit zero-cross signal generator 8 (active low), 5 is A N + (A /
D conversion input section) A microcomputer (MPU) that calculates the effective value of the voltage applied to the lamp from the input power supply voltage and updates the phase angle; 6 turns on the triac 7;
A trigger circuit to turn off, 8 a lamp load, and 9 a lamp voltage target value setting circuit (input to ANO of 0 to 5vlJ<Mpu).

Next, the operation of the software will be explained.

In Figures 3 to 7, Figure 3 is the general flow;
4 to 6 show the flow of each interrupt process, and FIG. 7 shows the detailed flow of 5TEP8 in FIG. 3.

The above flow is an example of (■) in FIG. 1, that is, when the phase angle is updated for each wave to control the lamp voltage.

The microcomputer used in this example is the μC0M7811, which is a 1-chip 8-bit microcomputer with an A/D converter, an 8-bit CPU, ROM (4 bytes), RAM (256 bytes), A/D converter. D
Converter (8 analog inputs), multiple [1 m 16 bits]
Timer/event counter (2), 8-bit timer (2), general purpose serial interface, I10
board (40 bits), interrupt function (3 external, 8 internal
) etc. are integrated into one chip.

Before we get into the operation explanation, let's talk about Honjitsu ATM! Let us explain the use of a function with an example.

(1), external interrupt (IN'r2) - this is I
If an interrupt occurs due to the detection of a 1γ difference edge of the zero cross signal input to NT2 (if the II interrupt is enabled), the process jumps to the zero cross interrupt routine and performs interrupt processing.

(2), Timer function: Two sets of 8-minute interval timers ('l''1MIRO2TIMER1)
Each timer 7 is composed of an 8-bit up counter, an 8-point 21 comparator, and an 8-point timer register (TM 0 , 1 MI). The operation is I' M +1 or i'' M
I I-, -j'' set the interval time and turn on the timer.
The up counter is counted up from 0 according to the specification of the remote register ('l'MM). When the contents of TMO or rMI match the contents of the up counter, an internal interrupt is generated when the up counter is reset.12 If re-interrupts are enabled, the interrupt routine is skipped and a timer interrupt is generated. Perform processing.

In this example, commercial t fi O) I! It is used as a 417 phase angle timer for wave number discrimination and lamp applied voltage.

Commercial '[ill L7) f@wavenumber discrimination C is TMO/
'rM1 should be set to 0.5SEC (IOMHz crystal is used), and the timer is started when the zero cross point is detected. 0.5 from the timer start point
The frequency counter is incremented every time a zero crossing is detected during SEC. After 0.5 SEC has elapsed, the timer is stopped and the frequency counter is checked. If the counter is greater than 55, 60Hz, 5
If it is 5 or less, it is set as 50Hz. In this case, timer interrupts and zero-cross interrupts are disabled.

In the case of the phase angle timer, the input clock of TIMERO's up counter is 1.2 μS E C, and
Enter 0. TIMP, RI amplifier.

The large cross of the counter is the coincidence signal of TIMERO's up counter and TMO, which is 30X1°2-36μS
EC. Phase angle timer data is set in TM1. Then, at the zero cross point, TIMERO/l
Count up the up counter from 0 and set TIME.
When the up counter of RI and the contents of TMI match, a timer interrupt is generated, a jump is made to the timer interrupt routine, and timer interrupt processing is performed. In this case TIME
Disable RO interrupts and enable TIMERI interrupts.

(3) Analog/digital converter (A/DC) function ------- Among the 8 analog inputs (ANO-AN7), a lamp voltage target value setting circuit is connected to ANO, and the lamp voltage target value setting circuit is connected to ANO. The target value of the lamp voltage is determined based on the level (0 to 5 V). A voltage comparable to the commercial power supply voltage is input to AN1.

A/D conversion is performed from the time of the timer interrupt, and the results are stored in four registers (CRO1CRI, CR2 and CR3). However, CROlCRI, CR2 and CR3
A/A of ANOlANI, AN2 and AN3 respectively.
D conversion data is stored. (AN2 and AN3 are not used) When the data is completed in the four registers, an internal interrupt is generated, jumps to the interrupt routine (Al1), and performs A/D interrupt processing. A/r) conversion is repeated sequentially from CRO, regardless of whether the interrupt is accepted or not.

(4) Boat function - All boats are human output boats with output latches, and input/output specifications for each boat are set in each mode register.

Now, in Figure 3, when the power is turned on, 5TEPI:
Perform initial settings. In other words, reset each boat and clear all boats.

5TEP2: Next, detect the frequency of the commercial power supply.

The detection method has been described above, so a description thereof will be omitted.

5TEP3: When the frequency detection of the commercial power supply is completed, the phase angle timer register (PHA) is set to 13 for 50 Hz.
9.60) Set 115 for f z. This corresponds to a phase angle of π/2 radians. Then, zero-cross interrupts and timer interrupts are enabled.

5TEP4: Next, set the lamp voltage target value (SETRMS)
Set. In other words, ANO A/D conversion data (AD
Set (SETRMS) from formula 0 based on SET).

(SETRMS) - 1/4 (ADSET) + 75
■However, since A/D conversion is not performed the first time (SR1”
RMS) is 75.

5TEP5; Check the arrival of zero cross here,
To determine whether a zero cross has arrived, which is held until the zero cross arrives, check the zero cross arrival determination flag, and when the zero cross determination flag is 1", it is determined that a zero cross has arrived. (The zero cross arrival determination flag is inverted at the zero cross interrupt 5TEPa. ), when the zero cross arrives (CYCLEO), proceed to 5TEP6.

5TEP6: Same as 5TEP5, check for arrival of zero cross, and when zero cross arrives, that is, if zero cross determination flag is 0'', 5TEP7 (CYCL
Proceed to EI).

Between this STE P5 and 5TEP6 (CYCI, E
0), a series of interrupts occurs: zero-crossing interrupt STEPa → timer interrupt 5TEPb → A/DC interrupt 5TEPc.

5TEPa (Figure 4): When a zero cross is detected (falling edge), a zero cross L:7 interrupt is generated.

5TEPa -1: Disable A/U1c interrupt.

5TEPa-2: Turn off the lamp drive signal (trigger).

s'rEpa-3: Ze I] Invert the cross arrival determination flag.

5TEPa-4: Check whether the lamp is on or off, and if it is in the lamp off mode, S i' E Pa-
Go to 5, if it is lamp lighting mode, S T E P a-
Proceed to step 6.

5TEPa-5: Phase angle timer/L-distor (PHA)
Save the contents of 'rM1' and proceed to STEP a-8.

s"rp:pa-6: Checks whether it is time to start lamp lighting, and if it is time to start lamp lighting, STE Pa-
7, otherwise go to S ``I'' EP a -5.

5TEPa-7: Set the phase angle timer at the start of lamp lighting to T.
Set to MI. The nuclear phase angle timer is 250 for 50 H2 and 208 for 60 Hz.

STEPa-8: Count up the up counter of TMO/1 from 0.

When the above zero-cross interrupt processing is completed, the process proceeds from 5TEP5 to 5TEP6 in FIG. While waiting at 5TEP6, a timer interrupt at 5TEPb (Fig. 5) occurs.

That is, when the time set in the phase angle timer TMI elapses, a timer interrupt is generated, jumps to 5TEpb, and timer interrupt processing is performed.

5TEPb-1: Stop the TMO/l up counter.

5TEPb-2; Check whether the mode is lamp lighting mode or not. If it is lamp lighting mode, turn on the lamp drive signal to light the lamp.

5TEPb-3: CYCl, BO or CY CL E 1
CYCLEn (if the zero cross determination flag is “1”) starts A/D conversion, and
/Enable D conversion interrupt. A for CYCLEL
/D conversion is prohibited.

Next, A/D conversion interrupt 5TEPc (Figure 6q) occurs every 230 μSEC until the next zero cross is detected.

5TEPc-1: Store the data of (CRO), that is, the lamp voltage setting data in (ADSET).

5TEPc-21 (CRI) data, that is, the instantaneous value of the power supply voltage, is stored in the voltage A/D buffer register. In other words, at the first interrupt, (VOLTI),
At the second interrupt, (VOLT2)...
At the nth interrupt, it is stored in (VOLTn).

Next, when a zero cross is detected, a zero cross interrupt is generated, and the zero cross interrupt processing 5TEPa' (Figure 4)
After doing so, proceed to 5TEP7.

5TEP7: Here, the effective value (RMS) of the lamp voltage is calculated from the A/D conversion data. In other words, the square product value of A/D conversion data (SUMSQR) (SUMSQR) =
(VOLTI)” +(VOLT2)Tomi+-+ (VO
l, Tn)" ■, and the value (A
VE) (AVE) - (StJK4SQR)/SPTI
M ■ [Here, SPTIM is 43.
In the case of 60 Hz, it is 36].

seek. Then, the root of (AVE) is calculated and the effective value (RMS) is determined.

(RMS) = JI, -j (AVE)
@5TEP8: Next, update the phase angle of the lamp voltage.

As shown in the detailed flowchart (FIG. 7), 5TEP8-IF First, the decrement (!(nlFF)) of the phase angle timer at the time of soft start is determined from the formula 0.

5TEP8-2: Check whether or not the lamp lighting mode is on. If it is the lamp lighting mode, proceed to 5TEPII3, and if it is the lamp lighting mode, proceed to 5TEP8-4.

s'rEpa-3: Difference between target value voltage (SETRMS) and detected effective value voltage (RMS) (SETRMS) - (RM
The value obtained by subtracting S) from the phase angle timer data (PHA) is set as new phase angle timer data (PHA).

5TEP8-4: Check whether soft start is in progress. If soft start is in progress, proceed to 5TEP8-5. If in steady mode, proceed to 5TEP8-3. To determine whether soft start is in progress, check the soft start flag. ,
That is, the soft start flag is set in the lamp off mode. When the lamp lighting mode is entered and (Sf: 'rRMS)≦(RMS), the soft start flag is reset. Therefore, when the soft start flag is "13", the soft start flag is When the start flag is '03, the mode becomes steady mode.

5TEP8-5F The value obtained by subtracting the soft start phase angle timer decrement value (DIFF>) from the phase angle timer data (PHA) is set as new phase angle timer data (PHA).

When 5TEP8 is finished, return to 5TEP4. This 5TEP
A timer interrupt occurs between 7 and 5TEP4, and timer interrupt processing 5TEPb' (FIG. 5) is performed.

(Effects) The present invention is as described above, and according to the lamp voltage soft start control method according to the present invention, it is possible to always obtain a constant soft start time even if the power supply voltage or set voltage changes. Therefore, when applied to a copying machine, the leading edge of copies does not become black, and stable, high-quality copied images can be obtained.

[Brief explanation of drawings]

FIG. 1 (summer), (11) is a diagram showing the transition of the phase angle αS of the soft start control method according to the present invention, (H is when the phase angle is expanded every half wave and goes to C, (n) is a diagram showing the case where the phase angle is widened for each wave, FIG. 2 is a circuit configuration diagram according to one embodiment, FIG. 3 is a general flowchart, and FIG.
5 and 6 are flowcharts of each interrupt process, and FIG. 7 is a detailed flowchart of 5TEP8 in FIG. 3. Engraving of drawings (no change in content) Engraving of drawings of Figure 4 (no changes in content) Reading ft +1-mi (method) November 12, 1985

Claims (1)

[Claims] In a lamp control method in which the lamp lighting voltage is controlled by a microcomputer, the phase angle of the voltage equal to the set voltage level is determined when the lamp is turned off, and the difference between the phase angle and the phase angle when the lamp starts lighting is divided by the soft start time. The result is used as the decrement value, and the power supply is applied for half a wave or one time from the voltage at the start of lamp lighting until it reaches a predetermined set voltage level.
A lamp control method characterized by having a soft start mechanism that widens the phase angle by an interval of the decrement value for each wave.