12vDC to 16vAC board

[Junctionmad]

I’ve used a few of these low power inverter boards , all based around the same generator IC . 
 

firstly the 20khz is the switching frequency , the actual output is 50Hz , typically it’s a modified sine wave , which in general works “ OK” on most AC devices . Yes sometimes people can hear that frequency ( my wife can) , of course certain remnants of the switching frequency appear modulated onto the sine wave but generally this is not uncommon across cheap inverters 

 

power conversion efficient is typically mediocre , around 70% , ie around 700W of input power would be needed to produce an output of 500W 

 

( I chuckle at the poster suggesting you need huge input power ) 

 

however , there are typically several major drawback typical of cheap Chinese designs 

 

firstly the maximum output power is never attainable due to the inefficiencies and lack of heat dissipation. My tests show around 50% is achievable often less 

 

burst power is very limited so the ability to handle surges like motors etc is very limited 

 

the main weakness however tends to be poor overload management , meaning excessive power draw , shorts , etc are not protected against and as the input current is high , can result in quite spectacular failures , 

 

I would use them but only rated them about 20% of stated power and you need to know what you are doing ( ie limit / prevent any output surge currents or overloads ) 

 

by the way the inverters on Halfords and Amazon’s are all Chinese generally too and I’ve had one burst into flames as well 

 

Like all cheap stuff , to use them you need to understand the limitations and why it cost 2 quid  

 

If you want good quality fit and forget inverters buy European brands like Mastervolt or Victron or UK designed Sterling Power , the mains won’t sag , but your wallet will 

Edited October 10, 2019 by Junctionmad

[Junctionmad]

It should also be said that very few model railway items rated for low voltage AC actually need AC and you can feed them with suitable DC. Most modern AC driven devices simply rectify down the AC so can be fed with DC , some controllers relied on the 50Hz sine wave to provide a form of pulsing , but this isn’t now common ( Triac based controllers have largely disappeared etc ) 

Edited October 10, 2019 by Junctionmad