Questions tagged [backup]

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43 views

super capacitor's maximum charge current

I am designing a backup system based on a supercap and an LTC4041. The calculations by the guidlines in the datasheet brought me to the folowing parameters: Capacity:2.4F Charge current: 1A charge ...
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0answers
37 views

Pragotron clock control circuits

Greetings to everyone, A few months ago, I started creating electrical circuits. Im trying to produce a control circuit that will control the pragotron clock using the DCF77 module. My circuit also ...
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1answer
70 views

Super capacitor backup circuit

I want to implement a momentary power backup in my circuit using a supercapacitor. I have come up with the following circuit. Am I right in implementing the super capacitor like this? Also, the input ...
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1answer
58 views

5V battery backup supply for GPS

I designed a circuit to do the switching from a 12V car battery to a 8.4V Li-Po battery with a relay. Both batteries go through an LM7805 regulator to supply a constant 5V to a Raspberry Pi. When I ...
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2answers
73 views

Capacitor as power buffer for battery change

I have a quite simple question and quite a simple circuit in mind. I have an application, which is battery powered and uses a RTC clock for timekeeping. I would like to preserve the time during ...
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1answer
91 views

What could be causing my APCs to buzz from time to time, and for my Tesla to stop charging? [closed]

I have two issues happening at the same time (very much related). The APC brand UPS backups in my office all start buzzing at the same time, then click once every 5-10 minutes. This happens at all ...
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1answer
86 views

Power source switching/isolation circuit

I'm currently designing device which will be powered from external PSU but also will have backup power system from battery. I'm trying to solve my problem. When external power source is down (5V - USB)...
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0answers
17 views

Power backup for NiMH battery

I have a device powered by a 5S NiMH battery. The device sounds a low voltage alarm at 6.6v. When fully charged, the NiMH reads around 7v or higher. I have a few small boost converters. Could I hook ...
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1answer
68 views

2 x 90 Ah 12v deep cycle batteries in series runs 77-90w for under 20 minutes. Why?

I am trying to understand the maths here. I have 2x90Ah 12v batteries in series (24v) and they are powering my computer. The peak power is 120w while the computer is shutting down during a power loss. ...
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1answer
52 views

Altium Designer Deleted schematics completely

I opened up Altium after a windows update, and received this error: ...
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0answers
46 views

230V mains back up with 12V battery and inverter

I am looking to have a 12V battery back up if 230V is lost, to supply a mobile router for security cameras (solar charged battery powered) outside a house when vacant. I have a 130Ah battery in a ...
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0answers
19 views

Connecting Charger + Inverter to deep cycle battery

It's a really simple question I believe, but I just want to make double sure it's okay. Can one simply clamp a mains charger as well as an inverter onto a deep cycle battery, or does one need any ...
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2answers
231 views

Battery Charging Backup Circuit

I am relatively new to electronics and circuits. I'm modifying an alarm clock to have a battery backup. I've found a few circuits that show how to build a battery backup circuit and it makes a lot of ...
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3answers
142 views

Do home UPS (mostly advertised as inverters) have a rectifier built in?

This is regarding home UPS/inverters which are typically known to convert the DC from the battery to AC, so the AC can be used for household purposes. What I don't understand is how the batteries are ...
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1answer
52 views

Replacing Dallas NVRAM with larger capacity variant?

This DS1225AB-200 (8k x 8 = 64kB NVSRAM) is from 1995 and is probably dead (cannot measure from the outside.) The only close replacement in stock is a DS1230AB-100 (32k x 8 = 256kB.) Looking at the ...
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3answers
354 views

Using two diodes as a simple power supply backup switch

I saw this module as a "battery emergency switch module" for $2 on aliexpress: which is just a relay energized by the external power supply, and when the external supply is gone, connects ...
3
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1answer
111 views

Will this DC UPS with off the shelf components for home network and laptop work?

I am trying to build a DC UPS to power modem, router which have power requirements of 12V 2A and a laptop which has power requirement of a 20V 3.5A. I am planning to use a AC to DC SMPS which is ...
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1answer
125 views

DC backup battery switching module

It is common to find these cheap Backup Battery Switching on the internet. But the issue I have with these ones is the load gets reset when switching from the main source to the battery. It seems like ...
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1answer
398 views

is it okay 4 years old used UPS Battery filling sulfuric Acid insted of Distilled water?

I've 1250VA UPS where I found 2 battery (12V-9AH). which Is used for 4 and years more. When I brought this UPS it gave almost 80 to 90 minutes backup but now it only lasts for 15 min. so I decided to ...
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2answers
117 views

Same mAh, same volt - different current

I need to replace the 18650 battery of one application. The battery doesn't have any marking about volts, mAh or amperes. Because it's 18650, the voltage is fixed - done. mAh - will use 2000mAh (let'...
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1answer
166 views

Some basic questions about voltage and lithium power pack

Well, I've been stuck at home and since I've run out of things to do, I've started thinking about creating a simple cheap backup for my modem, router, and desktop fan. Since I've got several lithium ...
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3answers
68 views

crystal oscillator as backup (or with sync)

I have a device that generates a 49.152MHz frequency, but depending on its status it can cut it off from time to time. This frequency synchronizes my MCU's audio devices, but it must never be stopped. ...
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1answer
71 views

Replace 173 Wh lead acid battery with 20000 mAh power bank

I have an APC BX1100C 173 Wh UPS that I use for my computer. I also have a 20000 mAh power bank with output voltage of 5 V. What do I need to do to replace UPS battery with this power bank? Is this ...
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0answers
36 views

1 battery backup 2 garage doors

I have made a very simple battery backup for my garage door. 2 x 12v batteries in series and hooked into the battery terminals of my opener. This charges the battery and switches to backup on power ...
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1answer
57 views

Which among the circuit is the most efficient for battery backed up systems?

Which among the circuit is the most efficient one for a battery backed up solution. Would be helpful if you can state the reasons as well. simulate this circuit – Schematic created using ...
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1answer
103 views

Apc backup time calculation

I have APC BX1100C UPS for my pc. it has 2x7.2Ah battery. I have connected to it a router 12v 0.5a, and a monitor 19v 1.3a. Expected it to run 10 hours but it switched off after 2 hours. Does it mean ...
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1answer
51 views

Back-up battery

for a project I would like to design a system which would allow me to feed my application's logic rail from a back-up battery if the main battery would somehow stop functionioning (most likely due to ...
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1answer
52 views

Changeover relay circuit

I am looking for a circuit for one of mine typical application. I have transformer power supply with 230VAC/DC input with 12V /1A and 5V/500mA output. Now I wanted to introduce another stand by power ...
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1answer
38 views

Need help with terminology so that I can source a din rail version of this part

Im looking for a 12 VDC power supply that has the ability to switch to a battery when ac power is lost in addition to having some type of AC status function such as an open collector. This part does ...
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0answers
54 views

Power supply charging backup power - current flow via mosfet

I have following diagram on falstad Top +5V is main PSU (12V 10A). Bottom +5V is battery (12V 2.3Ah). I have load about 2-3A so I dont think diode is good solution. Well I am trying to achieve ...
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0answers
523 views

esp-12 power supply + backup by 4F capacitor 5.5v + ME2149, is it working?

I made my own energy meter using esp-12, I need to save data to esp spiffs when loss grid power, In this case, I do not need wifi than esp turn to modem-sleep mode, so working current is about 20 - ...
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1answer
959 views

how to switch to backup battery when power fail?

I have a project running with MCU supplied with a 24V power supply regulated via an SMPS to 9V also, I have Li-ion battery pack 9V how to connector these two sources to run the MCU with battery pack ...
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1answer
217 views

What happens to the backup time when batteries are connected in series?

I have a backup power system consisting of a charger, a battery and an inverter. The inverter powers my load (a few mains appliances). Currently I am using a 12V 200 Ah battery which gives me a backup ...
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2answers
213 views

Switch to battery when voltage supply drops certain threshold

I have made this circuit but can't quit make it work. Vext is my main supply from a car (9 - 14V) Vbat is 8 AA batteries (10 - 13V) Vout supplies power to a SMPS As it is now, supply "fades" between ...
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2answers
3k views

What will happen if I powered a 24VDC device from a 27.8VDC power supply?

I have a device which has a power input from 12-24VDC Auto select and 250 mA load. I connected it with an online DC UPS which has an output of 27.8 VDC on grid mode and 24 VDC on Battery Mode. I ...
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1answer
323 views

Integrated 5V uninterruptible power supply (UPS) with a lithium cell?

I'm trying to figure out the best way to implement a UPS for an embedded system that runs from a 5V supply. Essentially the system has a 48v to 5v, 1.2A output DCDC converter that powers my system. ...
2
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1answer
81 views

Ebedded Linux: Recoverable, battery backed-up RAM (/tmp) [closed]

I hope this is an appropriate place for this question as it involves the use of the kernel. I have an embedded system with a battery backup for the RAM chip. The battery also allows for the MCU to ...
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2answers
102 views

What would be the safest method to power a laptop (IdeaPad 510 15isk) from a 14.8v battery pack?

Looking at my existing power jack and measuring it crudely with a cm ruler it looks like 3mm diameter x 1 cm length. The laptop bottom and charging adapter both say 20v @ 3.25 A max. What would be ...
0
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1answer
236 views

5 seconds power supply backup for 12V 0.5A router

My country has a problem with the mains electricity supply, which cuts off and comes back straight away. My router restarts every time that happens. What I like to know is: What would be the most ...
2
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1answer
2k views

Creating a Li-on backup for a 12v router

I am building a small battery backup for my router with the 12V 0.5A DC input. Main use is to keep the router powered up during load shedding (aka. power cuts / blackouts ) while my backup generator ...
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3answers
1k views

Sram battery backup

I don't have an option here in my country , No non-volatile sram and i need it for my project . i designed a circuit for that and need anyone's opinion if it's ok or need a correction .
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1answer
45 views

Only Provide Backup Power to One Device On Bus With Cap/Supercap

In a robotic system I am designing, the computer, motor controller and motor amplifier circuits all run on the same 24VDC power bus, which is provided by a switching power supply. Like below: In the ...
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1answer
3k views

Coin cell battery recharging circuit for RTC backup power

I am designing a system that contains an RTC to for displaying the date and time on a user interface, as well as log events with time stamps. In this particular case, the system gets powered-on at ...
0
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1answer
56 views

Seamlessly powering 12v CPU fan with regulating speeds

I am trying to have an economical and reliable control system to seamlessly power two 12v, 0.3a CPU fans with varying speeds while also charging a 12v 7ah lead acid battery for backup. I could not ...
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2answers
484 views

Powering Multiple devices off one battery backup

I have a 12v3a battery backup with 1 dc barrel connector on the end. How can I power multiple 12v devices without needing to solder them, thus opening them and voiding the warranty. One device is ...
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1answer
229 views

Battery auto backup for GSM

I have a switching power supply that operates at 4V output. I want to have my GSM always powered when my primary voltage is removed. I use a simple Li-Ion battery 4.2V and I want to use it as backup ...