Hi everyone,
I'm trying to power a tp-link wireless router from a 15V battery system using a LM7805CT 5V voltage regulator and its has me a bit confused.
First off I should say that it's not the only device connected to the battery system. There's also a few other microcontrollers. The battery system itself is a fancy uC powered voltage regulator that has four 15V batteries hooked up, and always outputs around 15V. Without the router, the whole system draws just under about 300 mA.
As for the router, it works fine when I power it through a power supply, drawing a peak of 200 mA - I can connect to it on my computer and do all my business. It also works *sometimes* with the voltage regulator, but only when it's the only thing connected to the battery. Adding the rest of the devices means the router will power up, draw the correct amount of current, but not connect to my computer. Sometimes, however, with the router connected, the current from batteries becomes significantly larger, peaking at about 750 mA.
The original 5V power supply for the router is rated for 1A. All of my components should be able to handle that. I have a voltage regulator hooked up the a substantially sized heat sink as well. I've also tried adding bigger caps than the 7805 datasheet suggests (which are .33 uF and .1uF) - 10 uF on both the input and output.
Is there something I'm missing?
I'll try and get a schematic together ASAP to further illustrate my circuit.
I'm trying to power a tp-link wireless router from a 15V battery system using a LM7805CT 5V voltage regulator and its has me a bit confused.
First off I should say that it's not the only device connected to the battery system. There's also a few other microcontrollers. The battery system itself is a fancy uC powered voltage regulator that has four 15V batteries hooked up, and always outputs around 15V. Without the router, the whole system draws just under about 300 mA.
As for the router, it works fine when I power it through a power supply, drawing a peak of 200 mA - I can connect to it on my computer and do all my business. It also works *sometimes* with the voltage regulator, but only when it's the only thing connected to the battery. Adding the rest of the devices means the router will power up, draw the correct amount of current, but not connect to my computer. Sometimes, however, with the router connected, the current from batteries becomes significantly larger, peaking at about 750 mA.
The original 5V power supply for the router is rated for 1A. All of my components should be able to handle that. I have a voltage regulator hooked up the a substantially sized heat sink as well. I've also tried adding bigger caps than the 7805 datasheet suggests (which are .33 uF and .1uF) - 10 uF on both the input and output.
Is there something I'm missing?
I'll try and get a schematic together ASAP to further illustrate my circuit.