The specification for the power supply is 5V USB and 500mA Max.
I understand that I can only use a USB 2.0 port on the computer/laptop as USB 3.0 port is rated at 900mA.

Is there any report of TinySA failure(s) when the USB 3.0 port was used?

Thanks
Al

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My six sense is telling me?that I should be fine with the 900mA USB3.0. However, I am worried that the internal battery socket may fail if the current charging the internal (lithium) battery has no internal current regulator. Everything inside is Tiny!
I've heard people having such troubles with their NanoVNA by using a USB power charger rated at 2 amps instead of the 1 A max as specified.
Just saying...
73 Alain

开云体育

Connecting the TinySA to a USB port in a PC is safe, either USB 2 or USB 3, because both supply 5 V to its USB connectors and it is not a mater of currents asit has been already explained.

The problem that can happen using an USB charger, i.e. a phone fast charger, is that they can supply as much as 7V? to the phone and there is an internal regulator on the phone that takes care of it.? So as a caution, don't use an USB charger for charging the TinySA battery, use a PC or a USB power supply specified for 5.0 V output (BTW most of them).

Regards,

Ignacio EB4APL

My six sense is telling me?that I should be fine with the 900mA USB3.0. However, I am worried that the internal battery socket may fail if the current charging the internal (lithium) battery has no internal current regulator. Everything inside is Tiny!
I've heard people having such troubles with their NanoVNA by using a USB power charger rated at 2 amps instead of the 1 A max as specified.
Just saying...
73 Alain

I have used mine on a multitude of chargers and computers. On my laptops, the TinySA is hooked up via USB 3.0 with no problems.?
Ihave many USB power adapters in the house. Some capable of upwards of 4 amps, as well as a multitude of QC Capable USB chargers (5v,9v,12v). None of these chargers are of issue because of the way USB charger coding works. The device will not receive more current than what it tells the charger it needs. There are no USB chargers that will supply a higher voltage than 5v unless a capable device is attached (eg. Smart phone will tell USB charger "I can handle 9v @ 1.5amps") . Just don't use a cheap knockoff USB adapter and everything will be fine.

Rest assured there are proper battery charging ICs as well as a protection circuit on the little lipo battery that the TinySA uses. Both of which ensure proper charging and as well as protection from under and over charging.?


In other words, don't worry about the charging. The tinySA will be fine!

On Fri, Oct 9, 2020 at 01:45 PM, Alain wrote:

The specification for the power supply is 5V USB and 500mA Max.

The specification states the USB port or USB charger used should be able to supply minimum 500mA.
So any USB 2.0 or 3.x port will work and any modern charger (even the fast phone or tablet chargers) will work fine
There are USB chargers that can not supply 500mA (such as a USB charger intended for a low power device). There chargers may not be able to charge to tinySA.

Dear Gents,
I have attached a picture of the label of my TinySA. You can see that the current specification was (wrongly) labelled as "5V USB (500mA Max)".
This is the reason of my post/enquiry as I was concerned to have an increase of current supply from ~2.5 W (USB2.0/5V/500mA)?to ~4.5 W (USB3.0/5V/900mA).
Thank you Erik for this prompt clarification. In my opinion, it should be mentioned on the TinySA website if not.
All the best for now.
Alain

The current drawn by the tinySA is 500mA max, or less if less is needed

On 2020-10-10, at 11:14, Alain <aggaslondon@...> wrote:

This is the reason of my post/enquiry as I was concerned to have an increase of current supply from ~2.5 W (USB2.0/5V/500mA) to ~4.5 W (USB3.0/5V/900mA).

I have a table that is 74 cm high and can carry 300 kg load.

If I put something on this table, it will be at 74 cm height above the floor, regardless of its weight (if it is not more than 300 kg).

If I put something on the table that is less than 300 kg (say, a pencil), that will not be magically crushed by a 300 kg weight just because the table can bear that. The table will just happily bear the lighter load.

74 cm = 5 V — that is the voltage you get from the power supply; the supply will do what it can to keep up this voltage, up to a current of 900 mA.
300 kg = 900 mA — that is the maximum current it can supply, but the supply doesn’t force that current, that’s just its rated load capacity.

Of course, this all applies to constant voltage (CV) power supplies.
All USB power supplies are constant voltage (5 V), as are most “regulated” supplies.
(I also have constant current (CC) power supplies; these are not useful as USB power supplies. Just as constant voltage power supplies have a maximum current they can supply, constant current power supplies have a maximum voltage, often called the “compliance voltage”. But you don’t have one of those; they are quite special animals. Lab power supplies are often CV up to a rated/set current, which they then keep like a CC power supply — irrelevant unless you exceed the set current.)

And then there are power supplies that are not properly regulated (like a table that sags when I put something on top), so the voltage/current curve is more complicated. Use regulated CV supplies only.
(Note that there are also bad power supplies that may not be on spec;
simply only ever use power supplies from reputable sources, if only for electrical safety.)

Grü?e, Carsten

On Fri, Oct 9, 2020 at 04:05 PM, Alain wrote:

I've heard people having such troubles with their NanoVNA by using a USB power charger rated at 2 amps instead of the 1 A max as specified.
Just saying...

One can hear many *incorrect* things on the Internet, this is one of them.

On Sat, Oct 10, 2020 at 04:14 AM, Alain wrote:

You can see that the current specification was (wrongly) labelled as "5V USB (500mA Max)".
...

?In my opinion, it should be mentioned on the TinySA website if not.

The tinysa is *correctly* labeled. Look at any electrical device, the label specifies the current that the device will pull from the circuit.?

Look at *any* appliance in your home, it will tell you either how many watts or how many amps the device will pull, not what kind of limit has to be put on the supply.

You could put the tinysa on a 5 volt 100 amp supply and it would be perfectly happy, that's just simple electrical knowledge.

You plug things into your wall outlets that are capable of supplying many amps of power continuously, and hundreds of amps for a split second before the circuit protection trips. But you can plug in your computer, or lamp, or toaster without a thought, because electricity does not work the way you seem to think it does.?

I would suggest you go back to the basics and try and understand what people are trying to tell you.?

There is *nothing* wrong with how the tinysa is labeled, nothing needs to be changed.

As all has been explained I suggest we close this topic.

Thanks Michael for your assistance - Very much appreciated.
Al