This article describes self-loader with the AMP 4 LM324 op as a comparator, voltage reference set with a TL431, using S8550 as the adjustment control, the input voltage step-down, recharges the battery. Its features are simple circuit works reliably, without adjustment, easy to buy components and so on, the following description of several parts. apple iBook G4 14 inch battery apple MacBook 13 inch battery
1. The formation of the reference voltage Vref
External power through socket X, after the diode VD1 filter capacitor C 1. VD1 protective role in preventing damage when the external power supply reverses polarity TL431. R3, R4, R5 and TL431 composition of the reference voltage Vref, as the scheme parameter Vref = 2.5 × (100 820) / 820 = 2.80 (v), the data mainly for Ni-MH rechargeable designed for (single NiMH battery after the battery voltage is about full 1.40V).
2. High load current
(1) Working principle
Access to energy, power indicator LED (VD2) light. Insert the battery (see picture, actually leads to the battery box with son, batteries installed in the battery box), the time when the battery voltage is below Vref IC1-1 flow too low conduction VT1, the output current to the battery charge. At this stage, VT1 is to broaden the state – because the battery voltage and VD4-pressure drop and is about 3.2 V (assuming that to start charging Power when the battery voltage is approximately 2.5V), but after the voltage VD1 about 5.OV, therefore, manifold pressure transmitter VT1 – is much greater than 0.2V, the when the charge current is 300mA, VT1 heat worse, so better to use PT = 625mW of S8550, or increase the base resistance due to reduced charge current (Note: As the disk capacity Low LM324 is relatively low, measured IC1-2, IC1-4 output is low, 0V, is about 0.8 V). apple MacBook Pro 15 inch battery apple macbook pro 17 inch battery
(2) Loading instructions
First look at IC1-3 work: it’s the same with the side 1O feet across and Vref R13, R14 received positive feedback, the reverse side of 9-pin external capacitor, and a negative feedback path so it is actually a comparator with hysteresis. upper end of the beginning of C2 there is no tension, then the output of IC1-3 high. The two high discharge paths, a path through the R14 to 10 feet back the other way is to load resistance R15 capacitor C2 when the tension load in excess of 10 meters where the voltage V +, the comparator output switches low, the same time, because of feedback effects R14, 10 feet immediately below the V-voltage jump, this time, capacitor C2 discharges through resistor R15, when the discharge voltage of voltage below 10 V-pin, the comparator output and again turned up to R14 in the comments, once the 10-foot jump voltage V +, since the circuit was to repeat this process, therefore, IC1-3 Output for the fixed frequency square wave.
Second, review the work of IC1-4: battery voltage by R2, R16 partial pressure, and IC1-4 12 feet because R2 “R16, entry IC1-4 is essentially slightly lower than the voltage battery voltage of 12 feet, apple PowerBook G4 12 inch battery apple PowerBook G4 15 battery
It is obviously l3 feet in its lower part to voltage, IC1-4 output stability of depression. Combining the above discussion, we see that added to the R12 and VD 3 channel one end of the fixed frequency square wave electric
Pressure, the other end of a low and stable, therefore, periodically emitting diodes VD3, giving the impression of sparks.
Finally look at the work of IC1-1: When the output of IC1-2 low, apparently IC1-1-3 feet down, and two legs connected by R1 Vref Thus, IC1-1 is also the low production. Combining the above discussion, we see, R11 and VD5 both ends of the voltage difference is zero, therefore, VD5 (saturated instructions) can not turn on!
In addition, because IC1-a low-speed, regardless of the 9-pin IC1-3 changes of voltage (capacitor charging and discharging of the feet form a triangle voltage wave) are not affected by IC1-1 Release? Because IC1-3 9-pin voltage (or higher in the + V, or low-V) is always greater than the output of IC1-1, anti-bias VD6 break! So, this state, the work of three indicators were: power indicator lights VD2 normal blinks to indicate battery charge VD3 normal VD5 does not shine. apple powerbook g4 17-inch battery acer BTP-42C1
3. Small charge current
When the charging time, the battery voltage slowly rise to close to Vref when, IC1-2 output voltage has risen slowly, so the current flows through R7 slowly decreases, that is, current flowing in the basis of VT1 decreases gradually, then VT1 output current decreases slowly, but the battery voltage continuously increases slowly when the battery voltage is almost equal to Vref when, IC1-2 will output a higher voltage, IC1-and 1-3 feet high tension 2.8OV (RP-side input voltage 2-pin), the comparator output switches high. The voltage has two effects: firstly have VD5 partial conduction is turned on (At this point, IC1-4 output is low), indicating saturation charge, others are also VD6 partial conduction, while the R17 is small, in fact, C2 is required for the high-high, so IC1-3 power to 9-pin voltage higher than 10 feet, IC1-3 was forced to lower production, VD3 and without a positive bias.
While watching the performance of the external light load is off, saturated the lights at a time of instant conversion is complete, but in fact the charging process is a gradual transition: when the battery voltage is below Vref when the Sustained high charging current when the battery voltage when the load current decreases gradually up progressively responsible nil?? fires, even saturated, low current taxation continues! Therefore, this state, the three indicators of work were: VD2 LEDs indicating normal power; VD3 does not shine the light VD5 (towards saturation, low current load). toshiba satellite m50 battery toshiba satellite m55 battery
4. IC1-4 uses
From the above analysis of 2,3-content can be seen, if the circuit is large or small current load current, IC1-4 production was “weak”, this role if she does no, not as direct VD3, VD5 negative, then “the earth”? Firstly, the design does not consider the use of IC1-4, VD3, VD5 the cathode directly to ground. However, when the production of electricity, after good work has found a problem: when the battery is not installed, the saturation indicator VD5? Clearly inappropriate! Because without the battery installed in the micro-state VT1, CI 1-2 5-pin voltage is higher than that, IC1? 2 output is high, the production as high as IC1-2, light VD5.
If the route map IC1-4, do not install the battery VT1 a micro-state, IC1-4 12 feet higher than the voltage is, therefore, IC1-4 output is high, can not point VD5 light.
Need to explain that the voltage of external input can not be too high or too low. Heat pipe input voltage is too high, high charging current to resolve serious and, secondly, IC1-2 output is high time because the supply voltage higher than previously Vref (value), this will give us a false impression, the battery fills up quickly! not. Input voltage is too low is not good, as discussed above, IC1-2 because the output is high time to lower the supply voltage after the end or, worse, may never reach the battery indicator was flashing but the charge current during the process is long. Therefore, the external voltage is too high or too low, the care and control of the state of saturation is not correct. toshiba satellite m40 battery toshiba satellite m45 battery