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Showing posts with label track. Show all posts
Showing posts with label track. Show all posts

Monday, April 8, 2013

Track the damage capacitors elco with ESR meter

All technicians must have the same experience that the old models of aircraft generally have several common Elco its dry or down in value, mainly found in many brands of china plane. Eco is dry can cause a variety of disorders that are sometimes difficult to trace or even be able to make certain parts do not work at all, especially if used on a circuit that works at such high frequency SMPS (Switch Mode Power Supply) and the horizontal. Elco dry technicians sometimes make headaches and time consuming when you track the damage.


Many technicians get around this problem by directly replacing all existing Elko, the Elko-regardless of whether Elko is corrupt or not. It is generally quite successful. But sometimes the quality is not good substitutes Elko, so the damaged aircraft back after use for some time. Replace all of Elko is also a problem for yourself if the circuit is improved a lot using Elko. The use of ESR-meter proved to be the most appropriate choice to solve the above problems. We suggest that ESR-meter is a must-have tool for every technician after avo-meter.

Using ESR-meter weve made themselves at a cost of less than 50,000 rupiah we recorded a lot of advantages such as:

  • Elko track damaged by the time more quickly because they do not need to remove the Elko (in-circuit tester) one by one.
  • Elko only replaced damaged
  • Can be used to check the quality of new and used Elko. It is certainly advantageous to utilize part of the former ex-change machine pcb. Sometimes the plane is damaged due to repeated just posted a new Elko was poor quality.
  • Elko that if the check using the ohm-meter sometimes the results are deceptive. Because if you checked with ESR ESR-meter turns his already large.
  • Can be used to check the flyback is short in the primary coil (between the B + with a pin-pin-collectors), def a short yoke, the power tranfo a short primer.
  • To find out if re-chargeable batteries are still good. Re-chargeable battery that is damaged ESR was generally higher when compared to a still good.
  • To keep track of printed lines leaking / short
  • By comparing the capacitors are still good, ESR-meter can be used to check the value of thousands pf capacitor.
Note:
  • ESR meter can not be to find Elko leak or short. Fortunately rare short Elko damage.
  • ESR meter to check the fit only Elko with values ​​ranging 0.47uF and above.
Does ESR it actually?Parameters are generally owned by a Elko understood by engineers is the "maximum working voltage" and "capacitance value". In the real case there are several other parameters such as the "maximum working temperature" (85 or 105 degrees C) and "ESR" (Equivalent Series Resistance).Unless the practice is capacitive in Elko also has the characteristics of "resistive" caused by a combination of resistance to the legs, internal connections, plates and electrolyte. Thus form a resistive characteristic ESR, because if it is portrayed as if such be installed in series with the capacitance of Elko.Ideally, an Elko ESR is zero, but in practice this is impossible.Elko High voltage tends to have larger ESR than the low voltage ElkoElko with small values ​​tend to have higher ESR values ​​greater than Elko.Elko 105 degrees (C) tend to have higher ESR than Elko 85 degrees (C).


What Is the ESR-meter?
ESR meter is a kind of ohm-meter that can be used to measure the amount of "resistance" of Elko. Difference if the ohm-meter using a dc current (direct current) to drive the meter, then use the ESR meter ac (alternating current) with a standard frequency 150Khz. As had been explained that ideally Elko its ESR is zero. But this is not possible in practice. Elko good quality 10uF value is close to zero or more generally.


What is the cause of ESR Elko subject to change.
  • The first is caused because of the connection quality is poor constituents. It can be found in Elko Elko New and old.
  • Both are caused due to dry the liquid electrolyte due to evaporate or leak, which can be found at the old Elko. Are the consequences of large ESR Elko turned into?



Consequences of changing the value of ESR Elko
  • Elko is a working principle can be "in-fill and waste of" electric charge repeatedly. Thus ESR Elko-charging current will be passed this exile repeatedly in accordance with the working frequency of the circuit. And we certainly have understood that if bypassed resistor will generate heat flows in accordance with the magnitude of the current strength through resistance value and the corresponding magnitude. Similarly, the Elko with ESR, the greater the greater the ESR value of the heat arising in Elko, and the higher the frequency the greater the heat generated. This heat can eventually cause the electrolyte evaporates into a gas and seeped out, so the value of Elko will turn down. In the specific cases heat can even make Elko explode.
  • On a circuit that works at high frequencies Elko should have zero resistance to the high frequency signal. If the ESR of the resistance turned into Elko is no longer zero, and if the resistance value change is large enough to make the workings of the chaotic circuit.


Our experience with the use of ESR meter in the aircraft repair older model (the old plane), the first one we always do is:
  • Check out all the Elko with ESR-meter at the SMPS, Horizontal and Vertical and immediately replace it if the ESR problem.
  • Check visually (with a magnifying glass if necessary) solder-solder on the SMPS, the output Horizontal, Vertical output, and the CRT socket pcb and soldering again if there appears a problem or suspicious solder it.
  • Both of these were able to eliminate the difficulties that may arise and difficult to trace, so the use of ESR meter can shorten repair time.



How to use homemade ESR meter (calibration)
  • Once the tool is finished
  • Collect some old Elko is still good. Find Elko pcb traces of the plane, made in Japan or Europe the original (former aircraft engine change) because of generally good quality for use as a reference.
  • Grouped on the basis of a value less dar 2.2uF, 4.7uF is less than, less than and greater than 10uF 10uF.
  • Try using the ESR-meter to measure each group, and mark the position of the needle meter on each group
  • These markers can be used as a reference to the appointment of Elko ESR is still good.
  • If the meter needle to deviate less from the reference mark, the mean ESR Elko is not good.


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Saturday, April 6, 2013

Smart Tracker track anything from your child to shoes

The EPE Minder consists of two type- approved transmitter units and a receiver. If either transmitter becomes separated from the receiver, a buzzer in the latter part will sound.
The receiver is fitted with a switch to allow the use of only one transmitter if required.

MIND HOW YOU GO

This system was originally designed as a two-channel child alarm (to protect either a single child or two children at the same time) but many other applications spring to mind. For example, one transmitter could be placed inside a briefcase and another in a coat pocket. If the user forgot to pick up either of these items and walked away, the buzzer would sound in the receiver. The receiver must be carried on the per- son in a way that would make it practically impossible to lose it. This could be done using a belt clip, for example. Note that it will not be possible to use this system if either the transmitter or receiver were placed inside metal containers or if there were substantial metallic “screening” objects between them.

OPERATING RANGE
The operating range may be adjusted according to the intended purpose. However, it does depend on conditions. Adjustment is carried out by means of “aerial link wires” on the circuit panels. With all these in place, the range of the prototype exceeds 12 metres in open air. It will also work throughout several rooms indoors if required. If the battery voltage in either transmit- ter or receiver falls below a certain value, or if a transmitter is switched off, a buzzer will sound. The specified batteries in the transmitters should provide several hun- dred hours of operation. Those in the receiver should provide around 100 hours.

PERSONAL CODE
The EPE Minder uses a system of digitally encoded low-power radio signals,
which pass from the transmitters to the receiver. The code is different for each transmitter so that the receiver is able to distinguish one from the other. Type-approved, pre-aligned transmitter and receiver modules that operate at 433MHz. are used. No traditional “radio” skills are needed and no licence is needed for their use in the UK.

TRANSMITTER CIRCUIT
The circuit diagram for a single trans- mitter unit is shown in Fig.1. Current is
supplied to the circuit from a 3V “coin” cell, B1, via on-off switch S2 and diode D1. The diode provides reverse-polarity protection. It is best to use the specified Schottky device which introduces a smaller forward voltage drop, and therefore less loss, than a conventional silicon diode (0·2V rather than 0·7V approximately). Capacitor C2 provides a small reserve of energy and pre- vents the supply voltage from fluctuating. This stabilises operation. A low power 7555 timer, IC1, is set up in a standard astable (pulse generator) con- figuration. While switched on, this produces a continuous train of on-off pulses at its output, pin 3.The choice of resistors R1, R2 and capacitor C1 provide one pulse per second for one of the transmitters (Unit A) and one pulse every 1·2 seconds for the other one (Unit B). In fact, the timings are slightly longer but it helps to consider them as above. Also, the on times are much longer than the off ones in each case. The purpose of this will be explained presently.




RECEIVER CIRCUIT

Receiver module, IC1, requires a supply of between 4·5V and 5·5V. The 6V nomi-
nal battery pack, B1, is brought within range by the forward drop of diode D5
(0·7V approx.) This diode also provides reverse-polarity protection. Capacitor C4 charges up and provides a small reserve of energy. This will be useful when the battery is nearing the end of its operating life. When the supply voltage falls below some 4V, the receiver stops working and the buzzer will sound. Below around 3V, the buzzer itself will not operate so it is important to check operation each time the units are used. Receiver IC1 should be of the a.m. (amplitude modulation) type as specified in the components list. As such, it will respond to the on-off pulses provided by the transmitter. The inexpensive super regenerative (rather than superhet) variety will be perfectly adequate. The low-power variants of these receivers have not been tested. Although for battery operation they would appear to be ideal, the standard type is more readily available.

The receiver may be considered as hav- ing separate r.f. (radio frequency) and a.f. (audio frequency) sections. These have individual supply inputs (pins 1, 10, 12 and 15 with some being duplicated). These are all connected together and decoupled using capacitor C1.

TESTING

Having completed the Receiver board, we can now commence testing all three
boards. It helps to minimise the Receiver “hold-off” time by adjusting preset VR1 fully anti-clockwise (as viewed from the left-hand side of the p.c.b.) and preset VR2 fully clockwise (as viewed from the right- hand side of the p.c.b.). Check that the Test link has been left unconnected to prevent IC4b signal from passing to transistor TR1’s base. Switch on Single Channel switch S3 so that Channel A is enabled. With On-Off switch S4 off, insert the batteries. Switch on. After a short delay, the buzzer WD1 should sound. Now place Transmitter A approximately
three metres away from the Receiver, insert the battery and switch on. The buzzer should begin to bleep every second. The same procedure is now repeated for Transmitter B. To do this, switch S3 off to disable Channel A and firmly twist together the ends of the Test link wires. It is not advisable to solder this connection unless the i.c.s are removed first. The buzzer should bleep at a slightly slower rate than for Transmitter A. It is unlikely that the time periods of the two transmitters will be the same (due to overlapping component tolerances).
However, if they are, one of them will need to be changed. Choose slightly higher values for resistors R1 and R2 to slow it down and vice versa. Remove the i.c.s before making any modifications.

HOLD-OFF TIME
When both transmitters have been test- ed, switch S3 on to enable both channels. presets VR1 and VR2 should now be adjusted to approximately mid-track posi- tion. This should provide a sufficient “hold off” time plus a small margin. The buzzer should now remain off and only sound when one of the transmitters is switched off or moved out of range. Leave them operating for several minutes. If the occasional spurious bleep is heard, increase the settings of VR1/VR2 to pre- vent this happening.
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