Although this topic is very simple and very basic, we try to raise it again because we have witnessed a student / novice technician who still ignores the principles of work safety, as if they are indifferent to the procedure for measuring resources, if the resources they handle are small in capacity, the dangers caused may not be so obvious, but if it is approaching the medium level, let alone high! Wow, their lives could be in danger.
1. Measuring DC Volts
- Estimate how much DC volt you will measure. You can refer to the detailed specifications listed on the product body of the resource, whether it is a Battery, Accu, Solar Cell, etc. You can also refer to the supplied load, for example, the Accu body is plain and in its circuit it supplies Elco directly with a spec. 10Volt/100µF, then we can estimate that the Accu voltage is around 10 volts, then the MULTIMETER switch selector must indicate a number greater than 10 volts, you can use a scale of 25 or 50 volts.
- Attach the red plug to the positive pole, and the black plug to the negative pole.
- Pay attention to the number at which the needle stops, that is the magnitude of the measured voltage.
Measuring DC Volts
2. Measuring DC Ampere meter
- Estimate how much Current / Ampere you will measure. You can refer to the detailed specifications listed on the product body of the resource, whether it is Battery, Accu, Solar Cell, etc., then the selector switch is positioned at a larger number.
- NEVER measure Current / Ampere Directly meaning there is no bridging load, because if your MULTIMETER / AVOMETER is not qualified, the probe cable or jumper could burn because it gets excessive heat for a long time. Work around it with an appropriate load, such as in series with a Lamp or LED.
- Attach the red plug to the positive pole of the lamp, and attach the black plug to the negative pole of the battery.
- Next, observe the needle moving on the scale board, you will know how much current there is.
Measuring DC Ampere meter
Basics of Selection & Use of Electronic Test Equipment
Obviously, you will know what exotic testing tools look like, even most technicians use them. You may initially just follow suit, but you need to know that most technicians have their own reasons for using these tools with certain brands and specifications.
In many cases of handling electronic devices such as Radio, TV, and other signal processing devices, they certainly need complex information, not only Voltage, Current or Resistance, but also detailed wave information. Advanced instrumentation is clearly worthy for them.
DIGITAL: DMM (Digital Multimeter) / ANALOG: VOM (Volt Ohm Meter). I prefer to have both. Simpson 260 (oldest brand) is better in many ways such as measuring with the largest scale, while DMM is for measurements with high accuracy.
To check transistors, capacitors, resistance, diode function and PCB circuit connectivity, it will be more effective to use an Analog Multimeter, because sometimes precise data is not needed in the process of identifying errors/damage.
Test Probes
Make sure you have Test Probes with the best insulators, for your own safety when you are measuring at relatively high voltages. Test Probes below standard, with thin insulators or connectors, are highly not recommended for working at relatively high voltages/currents, because they can threaten your safety. Thin insulation cannot properly dampen high voltage radiation, while thin connectors cannot withstand the heat generated by high currents.
AC clamp-on Ammeter
This tool allows you to identify faults/damage to cables WITHOUT having to cut them multiple times just to narrow down the possibilities/enlarge the opportunities.
Dual Trace Oscilloscopes
Minimum Vertical Bandwidth 10 to 20 MHz, it would be great if there is a delayed sweep desirable, if not, it doesn't matter. The best probe setup is 10x / 1x. Electronic devices that are generally used by the public, on average only need a vertical bandwidth of around 10MHz. It's a different story if you enter the digital debugging stage, then it will be very possible to set the vertical bandwidth to 100MHz - and above.
You may not need an oscilloscope yet, but with this instrument you will be able to know many things, even more than just identifying errors. You will know the characteristics of each circuit block or even components that are still foreign to your eyes. Maybe this instrument seems luxurious to you, but it will not be wrong if you invest in this instrument.
Logic Probe
Logic Probe & Pulser
To perform a quick check on digital circuits. Digital pulses 0/1 can be detected easily and quickly.
Device Correlation Models
Providing electronic devices that are still normal, used as a correlation reference for trouble devices that are still similar to it.
Provides a VCR for testing I/O interfaces such as RF connectors and baseband (RCA jacks).
Audio Signal Generator
UNIT UTG9010A Digital Audio Ac Signal Generator
Its Amplitude generating function (sine, square, triangle) can be useful for triggering certain components or certain circuit blocks.
Audio Amplifier
FR4 94vo ROHS PCB Audio Amplifier 12v Dc Whole PCB Board And Components Sourcing And Assembly
The device is connected to a loudspeaker, the input must be selected between line level and mic level, still using the same ground, but the signal is led out of the circuit block and then directed to the Amplifier. This method is useful for tracing audio circuits that cause the main signal to go astray.
Injector Signal
A portable source that makes it easy for us to access the test tone of a signal (its application is very flexible) which can replace the role of the pre-amp amplifier so that it can be directly fed into the intermediate amplifier stage of a multistage electronic system.
RF Signal Generator
Radio Signal Generator which we know that radio signals are high frequency signals. To help in the process of debugging radio devices from tuners to final amplifiers, then we really need a capable device, it is quite expensive, but its role is irreplaceable such as the choice of modulation features and sweep functions.
Adjustable Power Supplies
At least I have one but it provides a wide voltage range, so one unit can accommodate a variety of electronic devices. I recommend at least 1 Ampere 0-40Volt.
Reference
- Test Equipment Projects You Can Build
- Delton T. Horn
- Tab Books, a division of McGraw-Hill, Inc., 1992
- Blue Ridge Summit, PA 17214
- ISBN 0-8306-4154-8 (hardcover), 0-8306-4155-6 (paperback)
How to Manage Engineering Equipment / Tools
If you have never heard of "HAND TOOLS", please just zoom in on the image below (right click >> open link in new tab).
1. Invest in the right tools
If you go to a technical equipment store, you can buy equipment with easy maintenance and also not expensive, so be selective. There is a lot of garbage out there, because equipment with specifications below your working standards will only frustrate you and eventually be idle, thrown away or sold at a low price.
2. Keep your tools fit
For example, maybe you can start with "Learning How to Use the Right Way" whether it's a wetstone (grinding wheel), drill, smart screwdriver, etc. And one thing you need to pay attention to is "DO NOT PLACE METAL TOOLS WITHOUT NICKEL IN A DAMP ZONE" or if not possible "YOU CAN PLACE LIGHT FILM / SUNLIGHT REFLECTOR DIRECTING YOUR METAL TOOL" this is one form of maintenance, keeping the tool from corroding or mossy. Another maintenance you can also spray WD40 into every gap of your Metal equipment.
3. Some Basic Hand Tools:
Screwdrivers (Screwdrivers), these are more of a standard type of screwdriver (minus and plus).
Jewelers screwdrivers (Decorative Screwdrivers), or types of screwdrivers with varied and complex screwdriver bits.
Small socket driver set, a kind of place with various partitions.
Small socket driver set
Hex key wrenches / hex drivers, also called Allen Keys or Hexagonal Keys because the tip of the key is hexagonal, there are also pentagonal ones. You may be more familiar with the term "Allen Key"
Pliers - long nose (long nose pliers), you must have used them.
Adjustable wrench (small), a kind of pass key but the size can be adjusted. You may be more familiar with the term "English Wrench".
Cutters - diagonal and flush, a kind of pliers but specifically for cutting models and sizes also vary.
Crimp tool, a tool used to strip cables, there are fixed and adjustable models.
Dental picks, this tool is useful for prying or poking into forbidden areas or the most difficult to reach areas, but you know how.
Anti-Static Alignment Tool Kit, used to adjust electronic components such as varco (variable capacitor), trimmer, RF coils, potentiometers, etc.
Locking clamps, usually used to open screws or bolts that are locked very tightly, sometimes also used to clamp something hard.
Hemostats, commonly used to tighten the smallest screws or bolts, are sometimes also used to clamp components when soldering.
Magnetic pickup tool, you never know when you will drop something, this tool will be very helpful for you to find the smallest components of metal, which are out of sight.
Solder and Attractor Solder is definitely a must for you technicians.
Electronic Equipment Repair Techniques
#Dismantle_Electronic_Equipment
Note: Equipment specification documents can also be added as supporting information, before you execute.
Yes, you will lose your warranty, but you know you are prepared for that.
Hint: A crowbar and a 6 kg hammer are the most comfortable resting places, really
#relaxingbro!
Manufacturers' equipment seems to be very good at making things mysterious, making us want to know what's inside, and how to open it. Not always, but it's become common knowledge. Opening equipment without damaging it is a very difficult possibility and a challenge in repair activities!
The variety of techniques used to open the cover of electronic equipment:
- Screws. Yes, many still use this old-fashioned technique. Sometimes we need to remove screws that are in the same part to make it stronger.
- Equip the screwdriver with various sizes of screwdriver bits and their physical sizes too, because we will never know how strong the screw locks the cover of the electronic equipment.
- Sometimes you find torx or other kinds of fasteners, and sometimes your manufacturer's tools don't support them, so you have to improvise to solve the problem. In an emergency, sometimes you have to worry about making it non-standard again.
- Hidden screws. Sometimes you need a pry tool to remove decorative stickers such as labels, or warranty stickers that are intentionally placed over screws. Sometimes you will also find rubber feet that cover screws or cover locks. Sometimes there are also some that are almost invisible to your eyes, so you need to feel for them to detect them.
- Snaps. Look at each side of the cover for what looks like a stitched pattern. You may need to use some force with a pry bar to get it open, but use a gentle rhythm so the Snaps don't break.
- Glue. Or more likely it is plastic that is attached to the cover. This is most common on adapter covers. And no doubt you will need a saw or sharp knife to get it off, although this may seem destructive but we have come to terms with it.
- This is all designed to improve. Don't laugh!. I think we'll see more and more unresolved public issues related to electronic devices. Some people get so frustrated that they throw them away.
- Never force anything, unless you are sure there is no alternative.
- The most annoying thing is when I find an endorsed device (an ex-service from someone else that is not working properly), so that I find many things that are disturbing, starting from incomplete screws, defective circuits, irregular component layouts, etc. The attitude that we need to take is to transparently inform the owner of the device and offer him the worst possibility, the decision to establish the execution steps is in the hands of the customer.
- When performing the recovery installation, make sure the cable route is correct and do not let anything get pinched or caught on components that have the potential to be hot, because the consequences can be fatal if a short circuit occurs.
For those of you who have difficulty opening the LCD:
Every home LCD / LED TV. Many of the most innovative screw placements are found, whether on the side of the screen, under the sticker or behind the flexible. You may need to use your sense of touch to help track. Also pay attention to the hinge section. Hope it's not awkward to do it, even though sweat often drips
By Onat Ahmet - onat@turbine.kuee.kyoto-u.ac.jp