Category: Review

This category will hold review articles.

Voltlog #171 – XFS5152CE Speech Synthesis Module Example Project

Welcome to a new Voltlog today we are taking a closer look at this inexpensive speech synthesis module. The part number is XFS5152CE and we do find a datasheet for this chip but unfortunately it is all in Chinese. The datasheet contains schematic examples, they show you how to wire a microphone pre-amp, how to wire an audio amplifier, they also give you some code examples but most of the text is in Chinese.

I found this online doc translator service which worked surprisingly well, it translated my document and kept most of the formatting intact. So now I have a translated datasheet which I will link in the description below and I will also place a link to places where you can buy this module and also where you can buy just the chip.

 

 

Voltlog #170 – Li-Ion Battery UPS Module Testing

In this video we are taking a closer look at the UPS Battery module I got in a recent InTheMail video.

Get this UPS Module: Ebay , Banggood. 

Datasheet links:

 

Voltlog #166 – LRC Reference Box (Hao QI Xin)

In this video we are taking a closer look at the Hao QI Xin LRC Reference Box which contains a couple of polystyrene capacitors, a vishay precision resistor and an un-marked inductor. I also talk about getting the AD584 voltage reference box, however it is hard to find the LH version as most seller will be sending you the KH version which is a lower grade of stability.

Here are some links mentioned in the video:

Voltlog #165 – USAMS 3 Port USB Charger With Display Review & Teardown

In this video I am taking a look at the USAMS 3 Port USB Charger With Display. Turns out the same charger is sold under many different names, and I suspect inside there is the same circuit labeled USB320G.

Like I mentioned in the past China is improving the designs of these charger each year so the situation is much better now than it was a few years back. There would still be the $2 death traps disguised as apple chargers but in the $10 range you can get some pretty decent chargers with adequate protection. This charger has the required protection features to make it safe to use however its not special in any way, the noise level is higher than I would like and the output current of just 3A is not enough for charging 3 devices. Not even 2 at the same time if they both require more current.

Here are links to where you can find this charger: Banggood, Aliexpress,  Amazon.

Voltlog #164 – Pirl USB Charger Review & Teardown

This is a review of the Pirl charger which has 4 independent USB ports each capable of up to 2.7A continuous output. The product will launch on kickstarter soon.

You get 4 ports each capable of 2.7A and we’ll put that to a test later. The 4 ports are independent so a fault on one of the ports is only gonna shut down that port. It has input reverse polarity protection, thermal protection and ESD protection. It can also detect and optimize the charging current based on the connected device so I expect to see one of those tiny chips which handles the usb data lines on each port.

Another interesting feature they mention on their website is voltage compensation such that each channel adjusts the output voltage according to the current drawn, if the current increases the voltage will increase slightly to compensate for the voltage drop that might occur in the cable up to your device.

They also have a wattmeter on the front of the device showing you how much power your device is pulling from the charger.

Voltlog #162 – Pocket Multimeter 1KV Testing and CAT Ratings

Welcome to a new voltlog, today we’re going to test a range of pocket multimeters by applying transient voltages to their inputs and we’re also going to talk a bit about CAT ratings and what they mean.

CAT ratings is something we often see marked on measurement tools and they refer to the measurement category, a method of classification published by IEC (the International Electrotechnical Commission). Different types of circuits will require a different measurement category based on the total energy available in that circuit. For example:

  • CAT I: is for measurements performed on secondary circuits not directly connected to mains.
  • CAT II: is for measurements performed on local electrical distribution, such as that provided by a standard wall outlet 110VAC in the US or 240VAC in the EU.
  • CAT III: is for measurements performed on hard wired building installation, for example distribution boards, circuit-breakers, bus-bars, junction boxes and industrial equipment.
  • CAT IV: is for measurements performed on the source of the low voltage installation, like the power input to your home, your electricity meter or the primary overcurrent protection device.

As you can see a higher CAT number refers to a circuit with higher available power and higher potential energy transients. Within each of these categories we have voltage ratings and a higher voltage rating means the ability to withstand a higher transient.

Welectron.com which is an authorized Brymen distributor, loaned me the BM887 Insulation Multimeter to perform some testing on the pocket meters.  I will be using this meter to apply 1KV to the pocket meters and see how they survive. The BM887 is made for measuring insulation resistance in industrial machines, certainly not for testing multimeter input protection but we can think of it as an abnormal voltage spike that might come rushing through a circuit you are measuring.

 

Voltlog #160 – Brymen BM22s and BM27s Pocket Multimeter Review

Welcome to a new voltlog, this is a follow-up on voltlog #148 the pocket multimeter shootout. In that video I reviewed 4 different cheap pocket multimeters. The general idea was that while some had advantages over others they were all missing important protection features on the input, making them safe to use only with low voltage, low energy circuits.

The guys from Welectron saw that video, they contacted me and said they have something better and they sent me the Brymen BM22S and BM27S for a review.

Welectron is offering a 5 EUR discount code (voltlog5) valid until 31st of May 2018. This will pretty much offer you free shipping for one of these meters which coupled with the 3 year warranty and their nice customer service, makes it a very nice deal if you are in the market for a good pocket multimeter.

You can also checkout my comparison spreadsheet to see how the Brymen meters compare against the other cheap pocket multimeters.

Voltlog #157 – Raspberry CryptoPI Designed For Mining Ethereum

In this video we’re taking a look at the new Raspberry CryptoPI, a single board computer designed specifically for mining Ethereum. It features 8GB of GDDR6 and a new Nvidia VOLTA GPU. Release date Q3 2018 at a cost of around $400 USD. Let’s hope there will be some units left for us because I am expecting whales to buy these in thousands qty.

  • Here is a link to the current Raspberry PI: Amazon,  Banggood. 
  • If you would like to support the channel you can donate here.

 

Voltlog #156 – Best Proximity Sensor For 3D Printer Auto Bed Leveling

In this video I am testing four different proximity sensors over the glass bed of my Creality CR10 3d printer.

Get the Creality CR10 3D printer from these places: Amazon, Aliexpress, or Banggood. 

Voltlog #155 – TL431 0-15V 0-5A Adjustable Power Supply Kit 3AG1 Xiaolin

A while ago I showed this power supply kit, which I ordered from ebay. It was being advertised as an LM317 0-15V 0-5A adjustable power supply kit and it looked promising. Upon receiving the kit and taking a closer look theres 2 thing to mention, one the power supply is not based on the LM317 but on the TL431, they used TL431s instead of op-amps in this power supply design and two there isn’t much documentation about this power supply.

The components used are low quality but that is to be expected from these cheap kits coming from china so no surprises there. If you would like to use some better quality parts I would suggest replacing the electrolytic’s and the TL431s with ones sourced from known sources. Also a nice upgrade would be to use some 10 turn pots instead of the supplied ones to get some finer adjustment. But I just used the originally supplied parts to see what kind of results we get with those.

Get the TL431 power supply from these links:

Here is a screenshot with the signal measured right on the bulk filtering capacitor (4700uF). Looks like this might be the cause of the 100Hz oscillation we we’re seeing on the output.

Here is a screenshot with the current overshoot. The power supply was set for CC 50mA and I suddenly shorted the output through a 1ohm resistor. The scope probe was placed across the resistor leads on the low side ( 1mV = 1mA ). As we can see we have a huge spike of current that could potentially fry an LED connected on this power supply. However the spike lasts less than 1mS which is good and I have observed similar behavior on my HP E3611A analog bench power supply.

Here is also a screenshot with the power supply regulating the current at 50mA in CC mode. This doesn’t look right at all.